# Creating CO2 naturally (Ended With Failure - insert sad kitten)



## Blue Ridge Reef (Feb 10, 2008)

I love that you're willing to experiment and applaud your efforts! I am skeptical of your design idea though. My initial thought is it might be impossible to duplicate nature this way in an enclosed system. The issue of raising of the pH and hardness is real, and from my limited experience with acid buffering soils, I think the limestone is going to exhaust them. So at best, every 6 months or year (how long it takes would probably be determined by amount of KH going in) the entire substrate would need to be replaced. And besides these ADA type substrates being pricey, that's not something we're going to want to do to our planted tanks. My second thought is the decomposing soil and the organics it would (surely) produce. Even if you can keep particulates out of the aquarium water, dissolved solids would be another matter. It's worth setting up and testing just for the potential knowledge gained though. It seems almost like a Bizzaro world calcium reactor. In spite of my skepticism of this working, I hope you do it and manage to work out all the kinks. The hobby needs something between DIY and pressurized systems. I promise if you make it work, we'll all call it the Minor Hero Method!


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## minorhero (Mar 28, 2019)

Thank you for the kind word Blue Ridge Reef!

Definitely the soil in the reactor should be exhausted eventually. That is one reason why I want a system where its easy to replace. In my mind I imagine this reactor to be kind of like a canister filter with stacked baskets of material. So many baskets of soil to so many of limestone etc. Then as the soil becomes exhausted you pull them out, replace with new soil and put them back in. Thats a bit far down the road. First I just need to see if it even works at all heh.


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## Blue Ridge Reef (Feb 10, 2008)

Oh, I misread and assumed that Aqua Soil was going in the display, not just in the reactor. That would certainly make it easier to replace than uprooting all the plants and starting the tank over. I do doubt that it packs nearly as much punch in the other direction as limestone, and the ratio would probably be very high in favor of soil to lime. Interested to see what you come up with.


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## Hilde (May 19, 2008)

I have been wondering the same thing. I have notice in co2 additive fluvic acid and humic acid are used. I have wondered if adding those products in the soil would create Co2.


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## minorhero (Mar 28, 2019)

An update!

So I decided to go ahead and do the experiment. When planning out the plumbing I quickly realized (actually it took several hours) that I didn't need 2 buckets. I could do everything in one bucket it just meant having the pump in the same container as my lime and soil. This is just an experiment and I don't actually want plants or fish in the bucket "aquarium". 

So with that in mind I went to the hardware store and bought some pellitized lime, 2 pool skimmer baskets, and some skimmer socks. I thought I already owned some potting soil but the only stuff I currently have is for cactus. So I will need to buy a small bag of potting soil next trip to the hardware store. In the meantime here is what everything looked like.










Next I put a small amount of lime into a skimmer basket with a sock.










I tried to wash the lime in this configuration but realized I was going to dissolve all of it this way since the lime is designed to dissolve into soil. I decided to just put in the bucket of water. If this works in the future a followup experiment will need to be done with actual limestone, which I could not find at my local hardware store, as this stuff clouds the water something fierce (frankly to be expected given what it is and what it is intended to do).

After that it was just a matter of setting back up the previous reactor experiment to dissolve some air into the water. Here is what that looked like:










I filled the bucket up last night and let it sit over night before doing the experiment this morning. Initial water parameters this morning were:

Ph: 7.8
Ammonia was between 0 and .26
GH 75
KH between 0 and 40
CO2 was somewhere around 1 to 2ppm.

I am going to let this run for at least 10 hours or so and then test C02 again. I will add soil probably tomorrow sometime and see how things go. I have no idea how long I would need to let it run with soil before there is any chance of seeing C02. I imagine a while since I need things to start decomposing. So at least several days.


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## minorhero (Mar 28, 2019)

And another update!

So some progress with the expirement with a positive result????? Well... Maybe.

So I tested the water today for CO2 and it appeared as if we were now at 6ppm. I say appeared because the darn water was so cloudy it was hard to be sure. Might have been higher or lower.

I decided it was time to revamp the expirement before I went further. If this is a positive result its already useless because the water was so incredibly cloudy it could never be used in a real aquarium. I pulled the basket of pellitized lime and completely cleaned out the bucket and reactor.

Here is what my lime looked like at this point:










As you can see its sludge having completely lost all form. This did not surprise me but I had hoped the sediment would have settled out a bit. Either the current was too strong or it simply dissolved too thoroughly into the water and it was never going to clear up.

I looked online for limestone and came up with a number of options on ebay but decided I had potentially another option closer to home. A while ago I "rescued" some rocks from the harsh wilds of my local area and brought them back for possible use in a future aquarium. I really liked how these rocks looked but sadly found them reactive when introduced to some vinegar. They have sat on my patio ever since. I figured it was time to make use of them! Now I actually have no idea what these rocks are but they are definitely sedimentary in origin and are reactive. My research showed they are likely limestone of some flavor and at the least are almost certainly carbon bearing of some kind. So they in theory should work just fine. Here is a picture of what they look like:










I dumped them into some fresh water and turned back on the pump. Now I will wait another 24 hours and retest the water. If I am still seeing an increase in co2 it will be really exciting. Either way I will introduce the soil to the process at some point after that.


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## minorhero (Mar 28, 2019)

So its been a little less then a day since I redid the bucket with my found rocks. I went out and tested the water for CO2 but it sadly showed only 1-2ppm same as my starting point. Whether this is because my rocks are not the right kind, or it just wasn't going to work with only rocks I don't know. Either way its time to add some soil to the mix and see how we do. I am going later today to the hardware store to pickup a bag of soil. I will report back once I have added it to the mix.


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## minorhero (Mar 28, 2019)

Update!

So I bought some potting soil, here is the stuff I am using:










Its not the organic kind but I hear the whole organic thing is uneeded in tanks anyway and I really just need something carbon based to break down so this should work fine for that.

To "clean" it I put it inside 2 pool filter skimmer socks, knotted the top of the sock so I didn't have the stuff floating away, and squirted with a hose till brown fines stopped coming out. This took all of 3 minutes.










Then I put it in the bucket and wouldn't you just know, the whole thing tried to float. So I put one of the rocks ontop. Here is how it looks now:










In other news I took a ph reading and found it still to be at 7.8. This did surprise me. If I had dumped large quantities of limestone into the water and let it sit for 24 hours I really would have expected a jump in ph. I mean there has to be volume wise about 1 gallon of rock in my bucket. Sooooo about 1/5th of my volume is rock and 4/5 water. I should be seeing something I would think. This makes me believe that I do not in fact have limestone at all. Soooooo yea I need to find me some limestone or shale, or possibly charcoal. 

I think I am going to buy me some proper limestone off of ebay or wherever I can find it. I apparently can not find it at my local big box hardware stores. 

I may also add some plant charcoal I saw locally to me which should be another excellent source of carbon for my water. 

Basically keep adding various things till I run out of ideas or get a positive result, whichever happens first ;P


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## Hilde (May 19, 2008)

How about trying black lava rock used in grills


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## minorhero (Mar 28, 2019)

RESULTS!

Well partial results anyway.

The experiment with dirt has been running for 6 days now give or take a handful of hours. I haven't touched it since then but the water level was starting to get low so I decided now was a good time to test before I am forced to add more water. The ph was as expected much lower then my baseline at around 7.2 and Nitrites were through the roof as again one would expect from what is essentially an uncycled tank with biological matter in it.

But most importantly I tested CO2. Results were 8ppm which is mostly good news! When I tested pellitized lime I got pretty much the same result. Now I have what I suspect are non-reactive rocks plus dirt in the bucket, and the dirt brings CO2 up to 8ppm all by itself. Does that mean if I can get my hands on some limestone I can double that number? Or does it mean that 8ppm is the max this type of system can sustain? I don't know but I am keen to find out. 

My wife and I put an offer on a house yesterday which has been distracting me from the important matters of the world such as running dirt and rocks in a pumped loop in my garage, but I will try and find a source online for some limestone in the next day or so. I actually have lots of sources, I just want one to be cheap darn it.


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## Discusluv (Dec 24, 2017)

minorhero said:


> RESULTS!
> 
> Well partial results anyway.
> 
> ...


 Much luck to you on the offer for the house. 



And cool experiment you have going...:smile2:


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## minorhero (Mar 28, 2019)

Hilde said:


> How about trying black lava rock used in grills


Unfortunately I need rocks that will be reactive in an aquarium. If the aquarium water is stable then they are not dissolving in the aquarium and thus I won't get the kind of results I am looking for. Lava rock is generally very stable so I think I need to look elsewhere. 


Speaking of which.. UPDATE:

So I got in the limestone I ordered from e bay. I was unable to find super cheap limestone like as in a giant sack of the stuff. I was however able to find limestone being sold as a teaching tool to geology students. The ebay business name is Geological Specimen Supply. They had the hilarious tag line of "Exporting the west one piece at a time". :grin2:

Anyway the advantage of using them was that I know exactly what type of rock I bought since it came with a handy dandy card telling me:










I paid about 12 dollars for my rocks and another 12 dollars or so in shipping. Here is what they look like:










I pulled out my old rocks that I suspect are inert, and added the new limestone to the tank. About half went to the bottom of the bucket, the other half is weighing down my dirt which definitely still wants to float. Here is what that looked like after I topped off the bucket with some fresh water:










Before adding the rocks and freshwater I did another test to see where the water parameters are at. 

PH: 6.8-7.0
KH: near 0
Nitrite and Nitrate: Off the chart
CO2: 8-9ppm

So now we play the waiting game. I am bad at the waiting game. I will likely get impatient and test again tomorrow. 

I have no idea how long this will take but I would consider this entire thing a gigantic success if I can get CO2 up to 15ppm. At that point we are at a level where some people purposely run their tanks if they are keeping shrimp. More would be better of course but I don't know if more is feasible with the quantities of soil and rock I have. If I obtain 15ppm I will need to start modifying the experiment from the wacky system I have now into something that looks like an actual reactor you could feasibly stick under an aquarium. 

Another possible advantage to using a system like this is as a means of getting fertilizers into a water supply. I have no idea how much nutrients are leaking from my soil bag but its got to be more then zero. /shrug secondary concern at best, just something I have thought about.


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## minorhero (Mar 28, 2019)

Update!! of FAILURE!!! Or is it??

Sooo... yea I have been testing the water every few days for the past month but not only have I not noticed an increase in CO2, in the past week or so I have noticed a decrease in CO2 from 8ppm to about 5ppm. This strongly implied to me that the CO2 producing life time of the soil was around 3 weeks or so in its prime.

Overall the whole thing was looking to be a bit of a failure. I decided to change up the expirement a bit by adding a larger air pump to the process. I bought one of these things and installed it yesterday. It advertised producing 380 gallons of air per hour which sounded like a lot to me. I installed it in place of my tiny Whisper 40 and noticed the output to be significantly greater then the Whisper 40. My reactor handled the additional load with not a single issue whatsoever. Not a bubble to seen. 

Wow what a great reactor I made. I pat myself firmly on the back and walk away.

I re-test the water late last night and notice not a single thing different. Still at 5ppm CO2. Well crud.

Then I get to thinking. Is my reactor actually that good? You know I never bothered to see if the air is getting into the reactor. I have no way of seeing into my reactor so I can't actually watch what is happening. But the only thing that is between my air pump and the reactor is... the check valve. 

The nice brass check valve I sprang for instead of the cheapy plastic check valves. In fact it is this check valve!

So I pull the airline hose off the reactor and wouldn't you know it.... no air... not a bit. Nothing is making it past the check valve. In fact nothing has ever made it past the check valve because the check valve is absolutely DOA. I know this because I removed the darn thing and plugged the airline directly into the air pump and bubbles start coming out the end of my reactor. And I never had that happen ever before strongly implying to me that this is the first time air has ever entered my reactor....!!!

Le sigh.

Anyway the experiment is now being restarted. This time with air! I have my whisper 40 back on because the air being produced by the other air pump was massive. My hope is to get some numbers that are a bit different then previous numbers. I may dredge up my previous experiment while I am at it since I clearly never properly tested whether regular air can actually increase CO2 in an aquarium.

The experiment(s) continue!


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## minorhero (Mar 28, 2019)

IT WORKS!!


TL;DR - I obtained 17ppm CO2

Since I last posted I was finally able to obtain complete dissolution of air into my reactor. I had to cut back the air flow all the way to about 3 bubbles per second to do this. This was of course quite the blow to my ego since I previously thought my reactor capable of doing much more. Air being harder to dissolve then water I have no idea how this stacks up compared to other reactors.

Anyway after getting things dialed in I waited and did a CO2 test 1 day later and the results... 8ppm. "Well crud" I thought. That is up from before but certainly not at the desired levels of at least 15ppm. I had a lot of hope that now that I was actually involving air it would be better.

At this point I had only 1 idea left. My thought for a while has been that the soil might not be providing the best biological breakdown of matter to release carbon into the water. I have wondered if it might be better to use something more compostable. To that end I raided my fridge. I found some salad "spring mix" that was a few days past its prime. I then opened my dirt bag in the experiment and removed half the dirt. I then shoved in the salad spring mix. 3 hours later I tested the water.

Result: 17-19 ppm CO2!

This is awesome news but its only the start. Now that I have achieved a useful result I need to do a LOT more work. I now need to isolate the variables and figure out what I did right. For instance, do I actually need the limestone? When I added it I noticed no bump in CO2. Do I need the soil? It certainly raised the CO2 but is the salad mix enough? Do I need the air reactor? Its possible it does nothing after all. And finally and most important of all, how long does it last and how stable is it? If it lasts 2 days its not very useful. If it lasts a month its very useful. If its not stable its also not useful. 

Next I will basically do nothing but monitor the situation and see what happens.

Still..... success!! :grin2:


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## Hilde (May 19, 2008)

😁


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## Hilde (May 19, 2008)

Looking forward to update


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## minorhero (Mar 28, 2019)

Update!

Remember when I said 17ppm? Well apparently that was just the start of the carbon release. I am now up to 34ppm.

Yes *34ppm!!!*

I am blown away by this. I was preening at 17ppm. At 34ppm there is as much or more CO2 in the water then most people are willing to run with their pressurized setups. 

Its going to be very interesting to see how long this much CO2 can be supplied.


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## Greggz (May 19, 2008)

Just curious.......how are you measuring CO2??


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## minorhero (Mar 28, 2019)

Greggz said:


> Just curious.......how are you measuring CO2??


I am using a LaMotte CO2 Test Kit. Linky


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## Deanna (Feb 15, 2017)

Take a look at this: https://www.plantedtank.net/forums/11-fertilizers-water-parameters/955-ph-kh-chart-vs-lamotte-co2-test.html#post6154

Can you get a good pH and KH reading?


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## cl3537 (Jan 28, 2019)

minorhero said:


> I am using a LaMotte CO2 Test Kit. Linky


I am sorry to inform you, but that Lamotte kit is useless the way you are trying to use it. All it is measuring is how much alkali(NaOH0 it takes to get to the phenolphthalein endpoint ph=8.3. Basically its measuring how much acid is in solution. If there was nothing else in your water except for CO2 which dissolves to be Carbonic Acid that would work but it won't be accurate if other acids or bases affect your pH.

You have a source of acid(soil?) + a source of base and carbonates (limestone), both completely invalidates the Lamotte kit titration.


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## aquaoz (Jul 17, 2019)

cl3537 said:


> I am sorry to inform you, but that Lamotte kit is useless the way you are trying to use it.


Is there any way that CO2 in this way can be measured correctly for the purposes of this experiment?


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## minorhero (Mar 28, 2019)

cl3537 said:


> I am sorry to inform you, but that Lamotte kit is useless the way you are trying to use it. All it is measuring is how much alkali(NaOH0 it takes to get to the phenolphthalein endpoint ph=8.3. Basically its measuring how much acid is in solution. If there was nothing else in your water except for CO2 which dissolves to be Carbonic Acid that would work but it won't be accurate if other acids or bases affect your pH.
> 
> You have a source of acid(soil?) + a source of base and carbonates (limestone), both completely invalidates the Lamotte kit titration.


I'm sorry but there must be a lot more to it then that. People's tap water varies greatly in PH. Are you saying someone with tap water with ph of 6 has some crazy number like 60ppm of CO2 according to this test whereas someone like me with tap water of 8.2 has 2ppm? 

If this were the case the LaMotte test kit would be 100% useless all of the time. I admit I do not understand the chemistry of what is happening with the test kit and I am very open to explanation of what is happening, but the kit can not simply be measuring how much solution it takes to raise the ph to 8.3

Edit: At any rate it is a good idea to come up with other means of testing CO2. The only other one I was able to find is a simple drop checker. Since the solution in the drop checker doesn't interact with the water it should not be thrown off by whatever I put in the water. I previously did not consider it because I did not think I would be reaching into the 30ppm level. Plus its not precise in saying how much CO2 is present. However, if we simply need to verify that CO2 exists in the levels we previously detected then it seems like a good option to double check the numbers. I will try to pickup a drop checker later today.


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## minorhero (Mar 28, 2019)

So I went to my local petco today (closest store) and bought one of these fellows:










Before installing it I took another reading using the LaMotte kit which reported approximately 42ppm of CO2. I then installed the drop checker in the bucket. The suction cup had no trouble sticking to the curved side which was good because I wasn't looking forward to finding something around my house I could reliable stick it to if that failed. Now to wait for a result. My understanding is that it can take a few hours for those things to change color one way or another.

Right now the biggest obstacle to overcome is going to be figuring out how to deal with all the organics I am introducing into the "aquarium." It currently looks and smells a bit like rotting lettuce water.... because it is rotting lettuce water. Here is the ongoing horror that is my test tank:










Its hard to see in the picture but those bubbles have a fainly greenish cast to them. I think some of this could be solved by containing the lettuce inside a very fine bag - as in the kind of material they make filter socks out of. A more realistic solution will likely involve using something that is not lettuce. Further testing will need to be done on other materials to find out if it has to be a leafy green to get this kind of reaction. Could you get similar results with something woody like sawdust etc. Excess tannins are easier to deal with then green slime I feel.


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## cl3537 (Jan 28, 2019)

minorhero said:


> I'm sorry but there must be a lot more to it then that. People's tap water varies greatly in PH. Are you saying someone with tap water with ph of 6 has some crazy number like 60ppm of CO2 according to this test whereas someone like me with tap water of 8.2 has 2ppm?


Correct the Lamotte test kit and Barr CO2 chart only works with theoretically perfect water, no other acids and bases other than Carbonate equilibrium. If you don't beleive me go and ask Lamotte tech support. There is no cheap magic way to measure CO2 in aquariums.



> If this were the case the LaMotte test kit would be 100% useless all of the time.


Ask Lamotte for the appropriate use case, I am sure there are many just not yours.

Bump:


aquaoz said:


> Is there any way that CO2 in this way can be measured correctly for the purposes of this experiment?


Not without expensive lab equipment and especially not if kh is fluctuating due to limestone.
If kh is staying stable(it doesn't appear to be the case here), than you can measure degassed tank water ph and then measure ph drop(ignore the charts) and assume 0.1ph drop = 3ppm as a rough ballpark.


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## minorhero (Mar 28, 2019)

cl3537 said:


> Correct the Lamotte test kit and Barr CO2 chart only works with theoretically perfect water, no other acids and bases other than Carbonate equilibrium. If you don't beleive me go and ask Lamotte tech support.


I did send an email to Lamotte tech support earlier this morning. If/when they respond I will include it here. I would be very sad if what you say is true because it means the LaMotte kit is truly useless to anyone not working in a water treatment facility which if that is whom it was made for I can't help but feel they would have better ways of measuring CO2. In the field measuring water from streams there would be rocks raising KH and there would be soil aplenty. So it would not be useful for that purpose either. Tap Water has all manner of products in it so its not useful for measuring that water either. I truly can't imagine a situation where you would want to use the LaMotte test kit if all it does is measure Ph. There are easier ways to measure Ph.

At any rate I did a look see on the drop checker. It looks to me like the top of the indicator liquid is turning yellow which would indicate the presence of "too much" CO2. I am going to wait a few more hours and check again. This is something that is not interacting directly with the water so it should only be changing color if CO2 is out-gassing into the vessel. This is what I would expect if the LaMotte test is accurate.


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## mgeorges (Feb 1, 2017)

My post was - 
I like what you're doing, but I have a major concern - the ability to control organics. The breakdown of the salad mix and the soil will release organics/carbs into the water which algae will thrive on, same as unhealthy leaves(and other variables) on our plants feed algae in our tanks. That's why good husbandry in the tank is so important to reduce algae. What's your plan to handle the organic load? It will be extremely high, I suspect, with this method.

I now see you mentioned this concern in post #25, I somehow managed to miss the second page of this as I was reading along, lol. If you figure out a way to deal with that much of an organic load, let us know. I think that alone will potentially be a killer for this if it is indeed generating that much CO2. You'd need a whooooolllleeee lot of Purigen or the like, but then would this continue to work with all the organics being trapped?


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## minorhero (Mar 28, 2019)

mgeorges said:


> My post was -
> I like what you're doing, but I have a major concern - the ability to control organics. The breakdown of the salad mix and the soil will release organics/carbs into the water which algae will thrive on, same as unhealthy leaves(and other variables) on our plants feed algae in our tanks. That's why good husbandry in the tank is so important to reduce algae. What's your plan to handle the organic load? It will be extremely high, I suspect, with this method.
> 
> I now see you mentioned this concern in post #25, I somehow managed to miss the second page of this as I was reading along, lol. If you figure out a way to deal with that much of an organic load, let us know. I think that alone will potentially be a killer for this if it is indeed generating that much CO2. You'd need a whooooolllleeee lot of Purigen or the like, but then would this continue to work with all the organics being trapped?


Thinking about how this would work in the aquarium has lead me down the path of essentially running a canister filter devoted to this process. Part of the canister filter would be whatever organics we are breaking down (and soil and rock if it ends up being needed) the rest of it would be filtration. The water would flow through the organics and then the filtration would remove the particles and the ammonia while leaving the co2. This is one possibility. Another would be to run some kind of system essentially inline with an existing canister filter or sump. Water comes in through the intake, goes through a container that has the co2 generating material, then leaves that container and continues on towards filtration. Having this much biological matter breaking down would mean we would need more biological media then what our fish bioload would normally require. How much more? No idea, it would be part of the testing process to figure out. how a system is designed will also be determined by whether we need dissolved air to bring this about. Would I still be getting CO2 generation without my air reactor? More testing is needed. Right now I am just at the point of watching my gross soup to see how long CO2 generation lasts. If I make it a week I will probably break it down to start testing the various ingredients of the system.

I am simply too interested in developing a better version to wait much longer then that.


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## cl3537 (Jan 28, 2019)

minorhero said:


> I truly can't imagine a situation where you would want to use the LaMotte test kit if all it does is measure Ph. There are easier ways to measure Ph.


It isn't, it is titrating how much acid is in solution, that is different from pH.
CO2 Reagent B is indeed NaOH and Water just look up the SDS on the Lamotte site.



> At any rate I did a look see on the drop checker. It looks to me like the top of the indicator liquid is turning yellow which would indicate the presence of "too much" CO2. I am going to wait a few more hours and check again. This is something that is not interacting directly with the water so it should only be changing color if CO2 is out-gassing into the vessel. This is what I would expect if the LaMotte test is accurate.


A drop checker is a blunt instrument with many caveats. I would suggest using my method and ignoring the kH changes, take out water from the tank and leave it 48 hours to degass then measure ph an then measure pH in your tank the difference will give you an indication of CO2 levels.


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## minorhero (Mar 28, 2019)

cl3537 said:


> It isn't, it is titrating how much acid is in solution, that is different from pH.
> CO2 Reagent B is indeed NaOH and Water just look up the SDS on the Lamotte site.


Chemistry was never a strength of mine so I unfortunately do not understand the distinction.

That said is there any reason why the drop checker would not work? Its definitely turning yellow from the top down. I will try to get a picture of it later tonight if I can find a good light source that doesn't give it an overly favorable appearance. Otherwise I will take a picture tomorrow when its in sunlight. 

To the extent the LaMotte test does not work, its odd that the drop checker is reporting the same thing (more then 30ppm of CO2). 

As for KH. I unfortunately do not currently have a good KH test. I have test strips but not the liquid test. I did however have a PH of 7.8 for many days at the start of the experiment before adding the lettuce to the equation. I also had pretty consistent results from the LaMotte test kit with everything in the system for over a month and it only changed when I added the Lettuce.


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## cl3537 (Jan 28, 2019)

minorhero said:


> Chemistry was never a strength of mine so I unfortunately do not understand the distinction.
> 
> That said is there any reason why the drop checker would not work? Its definitely turning yellow from the top down. I will try to get a picture of it later tonight if I can find a good light source that doesn't give it an overly favorable appearance. Otherwise I will take a picture tomorrow when its in sunlight.
> 
> ...


Take a sample of your water in a cup for 24 hours degass it, or run a bubbler through it for an hour, then measure ph.
Then measure ph of the bulk reactor water. If there is a significant difference between the two, and repeatable if you try it again, I would beleive that you have significant CO2 creation.


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## minorhero (Mar 28, 2019)

cl3537 said:


> Take a sample of your water in a cup for 24 hours degass it, or run a bubbler through it for an hour, then measure ph.
> Then measure ph of the bulk reactor water. If there is a significant difference between the two, and repeatable if you try it again, I would beleive that you have significant CO2 creation.


I previously had degassed my water and tested the ph at 7.8.

I just took another sample of tap water and will let it degass. That said, I also used my api master test kit to test the water in my experiment bucket just now. The test result was a ph of 6.6.


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## cl3537 (Jan 28, 2019)

minorhero said:


> I previously had degassed my water and tested the ph at 7.8.
> 
> I just took another sample of tap water and will let it degass.


Not your tap water, your 'reactor' water. If you indeed have 30+ ppm of CO2 than degassing it for 24 hours or with a bubbler should raise the pH as you release CO2 from the water. Take a sample from your reactor in a cup, test pH and then test it 24 - 48 hours later.


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## minorhero (Mar 28, 2019)

cl3537 said:


> Not your tap water, your 'reactor' water. If you indeed have 30+ ppm of CO2 than degassing it for 24 hours or with a bubbler should raise the pH as you release CO2 from the water. Take a sample from your reactor in a cup, test pH and then test it 24 - 48 hours later.


Ahhhhhhh

Heh, sorry completely didn't understand you before. This is a really good idea. I just scooped out a cup. Will check it again a few times tomorrow to see how it progresses.


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## minorhero (Mar 28, 2019)

UPDATE:

So I checked on everything this morning around 10am est. According to LaMotte its still showing approximately 42-45ppm of CO2. I also pulled the drop checker out so I could get a clear picture of it.

Here is how the drop checker looked yesterday after around 3 hours in the bucket. You can see the top turning yellow while the bottom is still blue:










Here is how it looked this morning:










So clearly the drop checker is telling me there is "too much" CO2 which to my understanding means more then 30ppm.

I also checked on my cup of degassing water. I pulled it out of the experiment bucket last night at around 10pm. So its had 12 hours to let off CO2 which means there is likely more to go. Here is what the Ph test looks like:











The one on the right is straight from experiment bucket today and shows a ph of 6.6. The one of the left is from my degassing cup and has a ph of 7.2.

I will check the cup again later today to see how its coming. This is the third day of the experiment since adding lettuce and its clearly still going strong. Pretty excited to see if it makes it the full week. I won't go further then that because its also incredibly nasty. I actually kind of hate sticking my hand in this bucket right now and I have never been bothered by getting my hands wet in an aquarium before. I think its pretty clear I am making CO2 at this point and at significant numbers, but this whole thing is worthless without being able to replicate similar results using a different material. The Lettuce system is too messy to be sustainable in the home aquarium.


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## minorhero (Mar 28, 2019)

Small update, the pH is up to 7.6 (19 hours after collecting). So that is a 1 point pH increase in a little under 24 hours.


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## theatermusic87 (Jun 22, 2014)

While you're running your test, it would be interesting to see what you ammonia/nitrate/nitrite readings are... I'd be willing to bet you have a fatal concentration of ammonia from all of that lettuce breaking down (not that that couldn't be potentially remedied with a cycled filter of course)


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## minorhero (Mar 28, 2019)

36 hours after removing a cup of water to let it degass and I think its about done. Ph at 10am was 7.8 so a 1.2 ph swing from the active experiment to the degassed state.

In other news I think the co2 production has peaked. Tested this morning with the LaMotte kit and it showed CO2 at 34ppm. The drop checker is also definitely shifting from yellow to green. This is day 4 of the experiment. Will be interesting to see how long it takes to crash. Will it still be producing useful levels in another 3 days or will it be done by tomorrow? Also, will other substances that are not lettuce (which I swear by everything shiny I will never use again) last longer?

Next thing I will try to run will be dried leaves with fresh or mostly fresh potting soil. I will check the CO2 reaction either tonight and tomorrow to see how it is doing.


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## Hilde (May 19, 2008)

Now i I wonder if you could duplicate the procedure. Then you would know exactly what you did right. What do you think is the main ingredient which increase CO2.


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## minorhero (Mar 28, 2019)

Hilde said:


> Now i I wonder if you could duplicate the procedure. Then you would know exactly what you did right. What do you think is the main ingredient which increase CO2.


Its definitely the lettuce in this system. The theory behind this experiment was to recreate what happens in nature. Its not uncommon to have streams and rivers with 30ppm of CO2 in nature. This is from either dissolving rocks, or the breakdown of biological matter, or both. I ran the bucket without lettuce for over a month and the most CO2 I could get was 8ppm. Added the lettuce and the CO2 skyrocketed. 

The soil I am using is just regular potting soil from my local hardware store, my thought when I bought it was that it might not have enough biological matter left in it to break down. If its not going to breakdown in the experiment its not going to release carbon into the water. That's why I added the lettuce, to put something into the bucket that I knew could breakdown and essentially rot. That rotting released a bunch of carbon into the water which bonded with oxygen to make CO2. 

My question at this point is if I could use other things like say, dry leaves, or organically produced paper, or saw dust? Or does it need to be some kind of green vegetable matter?


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## micheljq (Oct 24, 2012)

Very interesting and subscribed. Are the plants bubbling?

Michel.


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## Hilde (May 19, 2008)

How about a picture of the tank. Very interesting project. Does it smell? 
Just read an article about amino acids used to provide nitrogen for plants by G.P. Harris. L-arginine had great success so I am going to try that in filter.


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## minorhero (Mar 28, 2019)

I tested the water with the lamotte co2 test and a ph test this evening. Both concur with 18ppm CO2. I am officially calling the experiment to an end on this the 5th full day. I also tested the KH (via test strip) and it was crazy high 300+ and the ammonia (test strip) 6+. Nitrates were less then 10 and Nitrites were 0. So yea its not exactly welcoming to life at this point.

I would not advise anyone try this experiment with anything living right now. If anyone wants to try it with a bucket and a small pump for circulation I would highly encourage that, and would ask they post their results here so we can start getting multiple data points. 

If I get time tomorrow I will break the experiment down, wash it out as fully as I can, and then begin again this time with some dry leaves (assuming I can find some in my HOA community I am living in right now). And I will leave out the limestone since I am not sure its really adding anything to the CO2. It might be a few days though. My wife and I literally settled on our new house this morning so things are kinda busy right now. 

Ridiculous I know, but real life keeps intruding on my rotting lettuce water! Ohs wells, that's how it goes sometimes. ;P


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## Hilde (May 19, 2008)

Leaves from outside may have toxins on them. How about trying some almond leaves which are cheap on eBay


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## minorhero (Mar 28, 2019)

Hilde said:


> Leaves from outside may have toxins on them. How about trying some almond leaves which are cheap on eBay


I am not convinced the leaves you buy from ebay are any better. I got a pretty bad blue green algae outbreak after adding some of them without boiling a couple months back. I think if you are unsure if people are spraying the trees with pesticides then you shouldn't use leaves from the ground. I however am 100% positive that in a nearby "forest preserve" in my neighborhood that the leaves are left alone. No one is spraying 50-100 foot trees with anything.


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## Hilde (May 19, 2008)

Congrats on the house. Didn't think about the perserves for leaves. There is 1 near where I work. I shall have to try some leaves from there. Think I will boil them though.


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## theatermusic87 (Jun 22, 2014)

minorhero said:


> No one is spraying 50-100 foot trees with anything.


 Not entirely true, I work for a tree service and while it's not terribly common, we do foliar sprays on trees, usually for pest such as bag worms or airborne fungus... BUT you DEFINITELY know it's happening (think a miniature fire hose)

That being said there are lots of threads about adding natural leaves to aquariums with several options on what species to use. My thoughts on it are it's perfectly fine, but for your decomposition to take place faster I would look at using green fresh leaves, rather than dried (or natural fall) leaves as they tend to decompose slower.


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## minorhero (Mar 28, 2019)

Hilde said:


> Congrats on the house. Didn't think about the perserves for leaves. There is 1 near where I work. I shall have to try some leaves from there. Think I will boil them though.


Thank you! I am pretty excited for it not least because I am getting space for a bigger tank and also getting a workshop space.

Anyway back to the matter before us! 

I finally got around to cleaning out the bucket today and actually had enough time to get the experiment restarted as well. I went with completely fresh potting soil and also a bunch of dead/mostly dead leaves. I am pretty sure they are from a birch tree but honestly for purposes of this experiment I am not sure it matters. I just need something that will decay, whether its fish safe is less important right now since no fish will be going in the bucket. 

I grabbed all the leaves that would fit inside a 1 gallon plastic storage bag. Here is what that looked like:










I then added the leaves to my potting soil inside a doubled up pool skimmer bag. I squirted this with the hose for 5 or so minutes to wash off any small fines of dirt, then added it to the newly cleaned out bucket. I put a skimmer basket ontop of the bag because it wanted to float, and added some rocks I know are inert to weigh it down (quartz and gneiss). I then started up the pump. Here is how that all looked:










Overall pretty happy to no longer have a bucket of rotting slime in my garage. I took some initial readings. Straight out of the bucket immediately after filling up there was 2ppm of CO2. 0 ammonia, 0 nitrites, less then 20 nitrates (all via test strip). KH was 40-80 (via test strip). So nothing unexpected. Essentially all parts of the expirement are the same as before except I left out the limestone and I am using mostly dead leaves (though some had a little bit of green showing on them as they are newly fallen). 

Next up is a lot of waiting. Its unclear to me if this will even work before bacteria begin colonizing the bucket (essentially the time it takes to start up a new aquarium).


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## minorhero (Mar 28, 2019)

Quick UPDATE:

Just checked the bucket with the LaMotte test - we are up to 18ppm of CO2 approximately 7 hours after startup. Also it doesn't smell like rotting lettuce so huzzah!


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## ursamajor (Oct 6, 2015)

About your test kit...

I just looked it up. The kit is simple - one part is an indicator that changes color depending on pH. It is colorless in acidic (low pH) solutions and red in basic (high pH) solutions. The other is NaOH, which raises pH when added to solution. When you do the test, you're adding the NaOH to raise the pH (or neutralizing acidity) until the indicator changes color. The more acidic the solution is, the more NaOH you need to add. Since CO2 makes water more acidic, theoretically you can estimate how much CO2 is in the water depending on how much NaOH you have to add until the pH is high enough that the indicator changes color.

The problem is that you're adding loads of materials that release organic acids to the water. This drop in pH would register as an increase in CO2 to your kit, even if the CO2 didn't change.

I hope that makes sense. I do not think that you are getting accurate CO2 readings.

One other thing... One of the natural processes you're trying to replicate is the metabolic production of CO2 by living things. Why not just use a DIY CO2 reactor with yeast and sugar?


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## minorhero (Mar 28, 2019)

ursamajor said:


> About your test kit...
> 
> I just looked it up. The kit is simple - one part is an indicator that changes color depending on pH. It is colorless in acidic (low pH) solutions and red in basic (high pH) solutions. The other is NaOH, which raises pH when added to solution. When you do the test, you're adding the NaOH to raise the pH (or neutralizing acidity) until the indicator changes color. The more acidic the solution is, the more NaOH you need to add. Since CO2 makes water more acidic, theoretically you can estimate how much CO2 is in the water depending on how much NaOH you have to add until the pH is high enough that the indicator changes color.
> 
> ...



This was a point that was raised earlier as well. But with the earlier setup the presence of CO2 was shown not only through the LaMotte kit but also through the use of a drop checker, and by measuring PH from degassed water coming from the bucket. All three testing methods agreed. For that reason I am continuing to use the LaMotte kit since it was proven accurate previously. That said, I also have the drop checker back in the bucket with fresh indicator liquid. It is starting to shift colors at the top so this would indicate the presence of CO2 as well. Once I get a sigificant enough rise in CO2 according to LaMotte I will also degass some water to test via ph. 

I am very interested to see if using dry leaves will allow for a longer production time then the previous setup with lettuce.


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## minorhero (Mar 28, 2019)

Another small UPDATE:

Checked on the bucket this morning. LaMotte showed CO2 at 40ppm. The drop checker was yellow with only a hint of green at the bottom. In fact it looked like this:










I went ahead and pulled a cup of water out to degass for a third check of CO2. Current PH is 6.6 according to my API test kit. I will check the degassed water in a couple of days.

I am not going to check with LaMotte kit for a few days. The drop checker has shown itself to be quite reliable. If I see it start to turn green/blue I will check CO2 with LaMotte at that point. The bucket is foaming a bit at the top (little water circulation and lots of organics) but doesn't smell near as bad as last time with the lettuce. 

My plan is to see how long I can produce CO2 using these leaves, if I can get usable levels above 5 days I will consider this a good medium going forward. After that I will restart the experiment and then remove the air from the equation to see if that alters CO2 levels.


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## micheljq (Oct 24, 2012)

Another idea, add citric acid or Seachem acid buffer in the bucket with limestone, it should eat the KH and produce co2.

Michel.


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## Hilde (May 19, 2008)

ursamajor said:


> One other thing... One of the natural processes you're trying to replicate is the metabolic production of CO2 by living things. Why not just use a DIY CO2 reactor with yeast and sugar?


Tried that! It smelled like beer in my small apt.


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## minorhero (Mar 28, 2019)

Update:

Today is day 5 of the expirement since adding leaves. At this point the reaction was in the teens when running lettuce. Looked in on the drop checker today and it was a pretty solid green. Here is what that looked like:










LaMotte test kit reported CO2 of 24ppm which is a little low but not as low as lettuce at this same point. I am going to let it run a few more days and see what happens. 

The bucket itself has a lovely layer of scum on the surface and the water has large amounts of particles floating in it (as you can see by what stuck to my gloves in the picture). But that is kind of what I would expect from putting a bunch of leaves and dirt in a mesh bag and dunking it in a bucket for a week without filtration of any kind. 

I also had pretty much forgotten about my cup of degassing water for the past several days so I tested today and got a PH of 7.8 which is pretty much what I expected since that is what my test bucket has come out to in the past after degassing. 

What is becoming apparent is that even if this can all be made to work smoothly and reliably in a manner in which people will want to use it, we would still need to refresh our biological material every week or even more often. That means the composter (as I have come to think of it) would need to be very easy to access and clean out. This would not work well as a solution where you could set it up and walk away from it for months on end. It seems there is an initial burst of CO2 production which is quite high and then it starts to dwindle. I didn't let the lettuce run any longer then 5 days because it stunk too much. The leaves don't really smell so I don't mind letting them run longer. It will be interesting to see if a full week in if they still are producing useful amounts of CO2.

To answer the question, I have never tried DIY CO2 but my understanding from researching it is that it produces inconsistent CO2 and most people who do try it end up stop using it shortly after starting because its too much trouble to deal with. This experiment is an attempt to come up with something better. Whether it works is very unclear.


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## minorhero (Mar 28, 2019)

Update: 8 days after setup there is still co2!

LaMotte measured in at 17ppm while the drop checker is a greenish blueish color:










I am reasonably happy with this result. While CO2 is not super stable that is likely a result of how I setup the system and the natural process at work. CO2 has an initial high burst with whatever bits of plant matter falling apart and converting to carbon followed by a slower and more prolonged release as the plant matter continues to decay. For someone who wants to be running 30ppm all the time I could see adding small amounts of plant matter to a system daily or every other day while someone who just wants a low level of co2 available could wait longer between adding plant matter and add smaller amounts. /shrug just some thoughts.

When I get some time I will break down the bucket and start again this time without my air pump involved. Just water circulating in the pump and back down into the bucket. I will again do dry/mostly dry leaves as my medium. If I get CO2 then I can begin the process of designing a device that can turn all this theory into a practical application.


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## ursamajor (Oct 6, 2015)

Just to make sure I understand, is the goal to make a sort of CO2 reactor that tank water will pass through and return to the tank?


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## minorhero (Mar 28, 2019)

ursamajor said:


> Just to make sure I understand, is the goal to make a sort of CO2 reactor that tank water will pass through and return to the tank?


Yes exactly. Basically replace/provide alternative to diy co2. I doubt anyone with pressurized co2 already installed would dump it for this system even if I get it working super awesome but folks might use this instead of pressurized when first getting started IF it works properly. That's a very big 'if' at this point.

Basically as of now I need to have the product of this reaction go through filtration before it could ever return to the tank. Whether that filter is built into the "reactor" or if it's simply something you put inline from your intake before it gets to your filter is unknown. Figuring that out is 2 steps away. First I need to know if I need my air pump to make this work or not. If I do then I have to build a very different reactor from one where I don't. If I don't I could probably use a small canister filter to make this thing work.


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## ipkiss (Aug 9, 2011)

Hmm. At this point it's like my old plants melting back into the tank's ecosystem. But I suppose when u start, u have no plants to melt back in the first place.


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## minorhero (Mar 28, 2019)

ipkiss said:


> Hmm. At this point it's like my old plants melting back into the tank's ecosystem. But I suppose when u start, u have no plants to melt back in the first place.


Yes its just like our plants melting but done on a much larger scale. A few leaves of our plants melting back is a pretty small amount of matter compared to what it is in my bucket right now. I have about 1 gallon of dried/semi dried leaves. Now this produced too much CO2 but you get the idea. Likely our tanks have CO2 being produced from organic matter decaying all the time. But its being done on such a small scale that our plants likely use that CO2 up pretty quickly so we don't notice it. If everything in our tank suddenly died we would likely see a spike in CO2 to accompany the deaths. Since we usually clean things out pretty quickly (or are not around) we likely don't physically witness this CO2 spike. Plus unless you are using something like the LaMotte kit or take constant ph readings, you likely have no way of noticing the spike.


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## micheljq (Oct 24, 2012)

About adding old dried leaves. I did experiment many found locally in the past. Oak leaves were moving the pH down but not a lot, however oak leaves last long in the water, they rot slowly. Maple leaves rot quickly, they can disappear in one week. The best i found which were moving the pH acidic and relatively quick, were alder leaves, alder cones, beech leaves. I live in Canada/Quebec.

This thread encourage me to try again.

Michel.


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## ursamajor (Oct 6, 2015)

minorhero said:


> Yes its just like our plants melting but done on a much larger scale. A few leaves of our plants melting back is a pretty small amount of matter compared to what it is in my bucket right now. I have about 1 gallon of dried/semi dried leaves. Now this produced too much CO2 but you get the idea. Likely our tanks have CO2 being produced from organic matter decaying all the time. But its being done on such a small scale that our plants likely use that CO2 up pretty quickly so we don't notice it. If everything in our tank suddenly died we would likely see a spike in CO2 to accompany the deaths. Since we usually clean things out pretty quickly (or are not around) we likely don't physically witness this CO2 spike. Plus unless you are using something like the LaMotte kit or take constant ph readings, you likely have no way of noticing the spike.


One of the main reasons we trim back dead and decaying plant matter is that it releases waste into the tank that promotes algae growth. Have you given any thought to what effects connecting a composter to your water column might have on algae?


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## minorhero (Mar 28, 2019)

ursamajor said:


> One of the main reasons we trim back dead and decaying plant matter is that it releases waste into the tank that promotes algae growth. Have you given any thought to what effects connecting a composter to your water column might have on algae?


Definitely, its all about balance. If we are adding a ton of natural nutrients to our tanks through composting plant matter then we will almost certainly need to cut back on fertilizers we are adding at the same time. What we are creating with a composter is basically a compartmentalized version of what occurs in nature. Dead organic matter is what in nature fertilizes plants.. or at least its a big part of it. But that also means if you run your composter closer to that 30ppm level of CO2 then you would need a large amount of living plants available to take up the nutrients. You couldn't run it at 30ppm and have like 1 or 2 slow growing plants in a tank. 

Or at least that is my theory. 

Will it work??? No idea, but I hope it does, because I think it would be a super spiffy addition to the hobby.


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## Hilde (May 19, 2008)

Possible to put all of those items in a canister filter?


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## minorhero (Mar 28, 2019)

Hilde said:


> Possible to put all of those items in a canister filter?


This is one idea I have had. I don't know if I can rely on the internal filtration power of the canister filter to keep all the bits of leaves and dirt from entering back into the tank.

Additionally its possible we would need to add more organic matter every day, or possibly every other day (imagine putting a leaf or two in every day) if so it must be very easy to add this or the system becomes impractical.

And now for an UPDATE:

I cleaned out the old bucket and removed everything to begin fresh. This time the plan is to add no air to the composter. Rather I would just run the bucket with a pump in the bottom to provide circulation and leave my "air reactor" out of the picture entirely. 

When I took everything apart I tested the air hose to see how much air was still coming out. Unfortunately the answer to that question was zero. No air was coming out. Adjusting the valve on the airline resulted in bubbles once more flowing. So at some point it got turned down or clogged up and no further air came out. When that happened I am not sure. It could have happened right after starting up the last run or it could have happened only the day before I turned it down. It does make me wonder if my fall off of co2 was because of lack of additional air? This is the trouble of only having one bucket running at a time. Each variable takes a while to test and there are a lot of variables. 

Anyway I am proceeding with the no air experiment and if I get a shortened length of co2 production or markedly less co2 produced then previously I will rethink the air situation. If I get essentially the same amount of co2 being produced then I will not worry about it. At that point its something that can be tested further in an actual aquarium down the road.

In keeping with my setup from the last time I went and collected some dry/drying leaves from the same trees as before. Then added soil to a pool filter skimmer sock and then added the leaves. Here is what this looked like:










After having cleaned and dried the drop checker I added new fluid. For reference this is how it looks when its brand new:










Then I added the whole thing to the bucket with the pump circulating water at the bottom and a few rocks ontop of a skimmer basket to hold everything down. The bucket had been circulating water for 24 hours prior to adding the leaves/dirt to try and degass any extra o2 that had been put into the water from the process of filling the bucket up. No idea if that was sufficient or not.. But I suppose we will find out in due time  Here is what the setup looks like now:










Next up is a lot of waiting. I will check the co2 level with the LaMotte test kit later today. If its like the previous runs then we should see at least 15ppm+ of co2 in 4 or so hours. By tomorrow it should be around 40ppm+ If its significantly less then we know the air being introduced into the water is relevant.


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## ntdsc (Jul 24, 2019)

I had the idea that using an actual real garden composter might work, ie whatever is used to make a strong manure smelling composter, because then it would create the type of foam seen below dams. If you have an aquarium or 33 gallon plastic bin that's buttressed between the window and a piece of furniture to keep the plastic walls from bowing out, and have at the bottom, dried dirt, dried grass clippings, and above, a large amount of leaves to settle over the dirt to keep the dirt from clouding (and of course water filled up to the top), you would need an aquarium bubbler, and a wavemaker that's used occasionally to keep the water from going to algae (and using rainwater as a source), which will get mineralised by the soil.

I'll have to research your idea, but if the idea is to get foam, then having a garden composter, a real one outside that starts to smell like manure, you could add small amounts daily. Also, it's my idea that a composter works partly because it's in direct sunlight that actually heats it, and if you couldn't use it outdoors, you could use it indoors by putting a heating element inside, and you wouldn't want to add real manure, but things like dried grass clippings or food waste to it, or whatever else is used to make compost. Having a heating element would also speed up the composting. It's true because greenhouses are contained and get extremely hot in summer, and a composter is completely contained in the sun. I'm not sure I would use any salted food though.


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## minorhero (Mar 28, 2019)

A bubbler would not work well in any situation where we want to keep the co2 we create around. It will degass the co2 much faster then it can be made.


In other news - UPDATE:

I checked on the bucket this morning (meant to do it yesterday but time got away from me) and to my surprise I did not have as much co2 as I expected. LaMotte reported approx 25ppm while the drop checker was bluish-green. It looked like this:










By this time last run the drop checker was yellow and I was getting 40+ppm from LaMotte. So it's either the lack of dissolved air creating less co2 or the leaves I am using are more dry this time and that is producing less co2. If it's the lack of dissolved air I would expect my co2 levels to drop off quicker then the previous times as the supply of oxygen already in the bucket get's used up.

If dissolved air is actually a vital component to this process it will change dramatically what a working co2 composter needs to look like. It also means that the last run may be mostly invalid since I know at some point my system stopped dissolving air.


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## minorhero (Mar 28, 2019)

Small Update:

CO2 is down in the bucket to 14ppm according to LaMotte. The drop checker is definitely more blueish today then yesterday though still showing some green tint. 2 days into this run and this is WAY lower then I was expecting. I really thought my dissolved room air was not doing that much.. I anticipated it not mattering for purposes of making a co2 composter. Now I am coming to the inescapable conclusion that a steady supply of dissolved air is essential for co2 creation through a compost method. The air supplied through surface contact is simply not sufficient. 

To test if this is the reason for such low rates of co2 production I am going to plumb back in my air reactor. Normally this would not be a big issue but my darn pump broke that I was using. I am currently using a different pump to circulate the water but that pump lacks the fittings to attach to my air reactor. I need to see if I can buy some fittings to make it work. If CO2 production increases dramatically as soon as I add my air reactor then we will have confirmation of this new theory.

Regarding my air reactor, the darn thing is huge at 29" tall and extremely bulky. I am frankly not at all happy with how inefficient it is at dissolving air. I am therefore thinking of creating a new method of dissolving air into the water. A modified venturi with a very slow flow of air is my current idea. This will happen at some point down the road. First I want to use what I have already been using to confirm or deny this latest development.


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## ntdsc (Jul 24, 2019)

Your reactor idea seems good. I was saying somebody could make a contained composter indoors with a light bulb heating it or a small heating element in a reactor, so it would produce a winey breakdown in addition to CO2, and gas off that into the water, but a water flow through a sock like you say seems good to get some of the soluble fibers from leaves and things. A composter that has grass clippings that has been dried out in the sun would produce nitrogen.

The one thing I've noticed is that going from 3 or 4 gallons to 33 gallons, the extra mass makes a difference, so a composter that is larger would probably be better, and gentle is better, because a real composter outdoors, and bringing it inside would be too strong, but what I did was just leave out a plastic tank, 33 gallons outdoors, with dirt and dried grass, and water to the top, and brought it indoors, and covered with a massive amount of leaves, and the water is good, but it would be better if I modified it, because that is my "tank", but if I did modify it with a composter filled with dried grass and leaves, and dirt maybe, and the tank would be perhaps just gravel and sand with plants, no dirt, I'll have to see.

Also, if somebody uses a plastic tub as a tank, it helps to buttress it between two pieces of furniture or the window sill and a piece of furniture or something so it doesn't bow out, because then you can fill it up with more water. I'm not saying this will work, but having sand and gravel as a substrate, and just dropping in small amounts of topsoil dirt mixed with a bit of clay under dirt might work, because I have that exact set-up in a sword plant in the window (1 gallon plastic container), the live leaves outside the water, and triple 10 fertilizer in it, but aquarium safe fertilizer would be gentler, because the dirt seems not to break apart when dropping in small amounts like that.


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## stormvisions (Aug 22, 2019)

Hi. Interesting experiment. I had been thinking about natural CO2 production myself but with one tank in the living room, and no storage the wife would go crazy with my bucket and hoses next to the sofa.  I was looking more along the line of using a mycelium based product like ExHale https://amzn.to/33XD2zF My thought was that you would have an air pump push air through a container with a lid and some water - say air bubbles in water, but the 'out' port is above the water in this humidity chamber, then this air passes into a bucket with a lid and the mycelium mix adding air, and pushing some CO2 out the egress port and into a gang valve along with your 'regular' air supply.

You would probably need the moisture to keep the moving air from drying out the mycelium fungus.

Something like this.


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## ntdsc (Jul 24, 2019)

stormvisions- You could generate foam in a separate composter that sits above the leaves, dried grass, and maybe dirt in the composter, because the foam that rises above (you'd have it in a cooler with a light bulb) should containe minerals, and you could scoop it out daily into the tank. I'm using rainwater to mineralise because tap water seems to spoil.

Also, having a tank seperate from the composter with sand and gravel at the base, and dropping in dirt, small amounts, seems to be good, if you have plants in the tank


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## minorhero (Mar 28, 2019)

stormvisions said:


> Hi. Interesting experiment. I had been thinking about natural CO2 production myself but with one tank in the living room, and no storage the wife would go crazy with my bucket and hoses next to the sofa.  I was looking more along the line of using a mycelium based product like ExHale https://amzn.to/33XD2zF My thought was that you would have an air pump push air through a container with a lid and some water - say air bubbles in water, but the 'out' port is above the water in this humidity chamber, then this air passes into a bucket with a lid and the mycelium mix adding air, and pushing some CO2 out the egress port and into a gang valve along with your 'regular' air supply.
> 
> You would probably need the moisture to keep the moving air from drying out the mycelium fungus.
> 
> Something like this.


I have not heard of this product before. I think you could simplify your design by making a sealed bucket and in that bucket put exhale and the air pump together. Two valves on the bucket lid. One is just a through valve that you hook the air pump output to and that goes to the aquarium. The other would be a check valve pointing in to the bucket so air from the outside could go into the bucket but not come out this valve.

You would need to use a really really really small air pump and then probably turn it down a lot as well. No idea how much co2 would get into your tank using this method. The big issue being that almost certainly more regular air would come in then co2. If pumped through a diffuser in the tank I have no idea if the regular air being pumped in would simply outgass all your co2 before it could reach the plants, but its definitely super interesting. A lot would depend on how fast the co2 production really is.


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## stormvisions (Aug 22, 2019)

It would be hard to measure and control CO2 production levels which I assume would vary by temperature and other factors but as a 'passive' constant CO2 production it could be interesting. In theory, the small bag I linked will provide a 128 cubic foot space with CO2 for 6 months. If you keep some humidity flowing in so it doesn't dry out, and there are no extreme temps to kill the mycelium I'm guessing it could live a very long time (a year or more?) as long as there was still wood/organic matter for it to decompose or you added some of its favorite food every 6-12 months I don't see where it ever runs out.


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## stormvisions (Aug 22, 2019)

micheljq said:


> About adding old dried leaves. I did experiment many found locally in the past. Oak leaves were moving the pH down but not a lot, however oak leaves last long in the water, they rot slowly. Maple leaves rot quickly, they can disappear in one week. The best i found which were moving the pH acidic and relatively quick, were alder leaves, alder cones, beech leaves. I live in Canada/Quebec.
> 
> This thread encourage me to try again.
> 
> Michel.



For the record I use some bay leaves from my spice cabinet for my shrimp and they last a long time though large amounts of them might present a problem as I believe they have some antibacterial/antifungal properties. I also boil some cinnamon sticks for a while to remove excess oils and use a couple of those in there. Mentioned because maybe a few of these leaves/bark in the miix will change the scent to 'rotting lettuce with a hit of bay and cinnamon' (which is sure to be a sucessful new Axe Body Spray scent).


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## stormvisions (Aug 22, 2019)

minorhero said:


> I have not heard of this product before. I think you could simplify your design by making a sealed bucket and in that bucket put exhale and the air pump together. Two valves on the bucket lid. One is just a through valve that you hook the air pump output to and that goes to the aquarium. The other would be a check valve pointing in to the bucket so air from the outside could go into the bucket but not come out this valve.
> 
> You would need to use a really really really small air pump and then probably turn it down a lot as well. No idea how much co2 would get into your tank using this method. The big issue being that almost certainly more regular air would come in then co2. If pumped through a diffuser in the tank I have no idea if the regular air being pumped in would simply outgass all your co2 before it could reach the plants, but its definitely super interesting. A lot would depend on how fast the co2 production really is.



One more thought if the bucket wasn't too big, and had a tight seal then you might not need an air pump. The pressure from the build up of CO2 would cause the out flow to 'burp' CO2 into the tank, which might (?) then cause the check valve at the intake to suck in air. Have to test that but in theory I'd guess that if the intake check valve had a lower 'cracking' pressure the pressure would build up and the CO2 valve which requires more pressure would burp, then the intake which would require less pressure could breathe.


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## ntdsc (Jul 24, 2019)

If you can generate foam on top in the composter, and you just have a tube larger than an airline going into the aquarium water, the foam is a liquid/gas hybrid that should draw into the tank on its own, probably if the tube is filled with water from the aquarium first, and I might add, if it's completely sealed it might generate more foam because gas would build up, and then it wouldn't need water in the tube. Also, compost indoors should also get hot on its own, and they usually use week old grass clippings left out in the sun, but if mixed with dirt, fine minerals should mineralise the water if rainwater is in the composter


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## Streetwise (May 24, 2019)

stormvisions said:


> Hi. Interesting experiment. I had been thinking about natural CO2 production myself but with one tank in the living room, and no storage the wife would go crazy with my bucket and hoses next to the sofa.  I was looking more along the line of using a mycelium based product like ExHale https://amzn.to/33XD2zF My thought was that you would have an air pump push air through a container with a lid and some water - say air bubbles in water, but the 'out' port is above the water in this humidity chamber, then this air passes into a bucket with a lid and the mycelium mix adding air, and pushing some CO2 out the egress port and into a gang valve along with your 'regular' air supply.
> 
> You would probably need the moisture to keep the moving air from drying out the mycelium fungus.
> 
> Something like this.


I wonder if you could adapt a double-chamber water pipe for this.  Another option could be science lab glassware and accessories.


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## N7QL (Mar 13, 2018)

I am subscribing to this! I had a similar idea but on a much smaller scale to drop/buffer pH. I can't wait to see how it does!


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## minorhero (Mar 28, 2019)

Update: An interesting development.

About 4 days into this latest run the co2 in the bucket dropped to about 8ppm which is what I consider to be normal for having a bunch of soil in the bucket as shown from earlier trials. Due to some silly plumbing issues not worth describing here it took me a couple days to hook back up the air reactor. At this point its back up and running. 

The air reactor has been running for 24 hours at this point and I just took another measurement. LaMotte is now showing co2 at 13-14ppm. Which is where I was on day 2 of this run. The dissolved air therefore caused a co2 increase. I believe this to be a result of having more oxygen in the water for the carbon to bind to when it becomes available. But I am no chemistry wiz so /shrug. I will turn the air on and off a few more times to see if this continues to hold true.


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## theatermusic87 (Jun 22, 2014)

I doubt that it's availability of oxygen to bind with, much more likely that the decomposition process involves aerobic process and bacteria that rely on dissolved oxygen to survive.


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## minorhero (Mar 28, 2019)

Update: The End

The experiment is over, and this is the end.

Results???

Failure - mostly failure anyway.

I discovered (at least for purposes of my own knowledge) quite a bit about co2 creation in aquatic environments. I have as a result of this come to certain conclusions. The first of these is that creating high doses of co2 in an aquarium the same way it exists in nature is kind of a pain in the butt. 

Basically to make this work I would need to feed small amounts of green vegetable matter to a composter daily or every other day. I would over time be able to kind of lock in how much by weight of a certain plant I needed to add to get the desired ppm level of co2 in the aquarium. 

The trouble with doing it this way is that 1) it smells, 2) depending on the time of year I may be more or less limited to what kind of plant I can compost. 3) This is actually more labor intensive then a simple diy CO2 setup thus defeating the entire purpose of the experiment (to find something better then diy co2).

I seriously considered going forward with it anyway and just building a proper composter that would by necessity include an added bit of filtration to try and catch all the gunk that the composter would generate. In the end I decided that if I (the creator) of said unit did not actually want to run it on one of my aquariums then it was silly to expect anyone else to want to (in the long run) want to run one on their aquarium. 

I briefly thought I was onto something with this last run of the experiment when I saw a sharp increase in my CO2 ppm. But I was unable to verify the results when I retested it making me think that either I did the test wrong before or some other factor was at play that I was not accounting for.

Either way after trying to turn off the air and back on a few different times and a few different ways I have noticed no difference in my current CO2 production which is around 8ppm at present.

So my ultimate conclusion is that co2 production in nature is caused by large amounts of decaying matter which make the water look all mucky. That if we want to recreate it in our aquariums we would need to live with mucky water or filter out the extra gunk. And finally, that ultimately recreating the natural way of co2 production (high doses of co2 anyway ie 15-30ppm of CO2) we would need a system that is significantly more of a pain to deal with then either diy co2 or pressurized co2.

So the experiment was a failure in its ultimate objective.

That said, I did have a lot of fun doing the experiment which was a secondary goal ;P

I am definitely not done with experimenting either, just done with this experiment.

There are neither beginnings nor endings to the cycle of my experimentation. But it is an ending.

Sneak peak at the next experiment:

It is an off shoot from this experiment. Basically can I increase water oxygenation without creating bubbles thus improving fish health while not allowing my co2 (which will be a pressurized system) from degassing.

Who knows??? Tune in next time to find out!


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