# balancing tank for no water changes



## seuadr (Feb 20, 2013)

tank: 36 gallon bow-front
light: 2x 42 watt 6500 bulbs
Substrate: Black fluorite, 2'ish inches
Ferts: flourish once a week or so
Filter: Fluval 205, with 2x bio blocks and a bag of carbon when the water starts to smell
Livestock: 3 harlequin tetras, 2 black neon tetras, 2 cardinal tetras, a bunch of MTS and other assorted snails, 2 amano shrimp and a gold platy.

plants consist of just sword chains. I had some amazon swords that got WAY too big for the tank, and the sword chains took over everywhere. I kind of like them, but i'm considering adding some more plants.

used RO water for 2 years, ended up just using Tap water to top it off. 

for the first 6 months of the tank, we did 5% water changes daily, dosed liquid carbon and macro/micro flourish products and did all kinds of maintenance. after about 6 months, everything stabilized pretty good. I went from checking it every day to once a week, then once a month. honestly don't know what i "did right" but i only add water once a month or so to replace evaporated water and feed the fish every other day with blackworms.


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## pwolfe (Mar 2, 2011)

I'm not so sure about this. As a hobbyist I think you'd be better served learning how to stabilize BY DOING water changes, rather than the reverse.


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## houseofcards (Mar 21, 2009)

naturelady said:


> I've read about how water changes are bad for no CO2 setups, because they re-introduce CO2 to the tank, upsetting the balance that the plants have..


That is really not true. Water changes will benefit any setup as long as your still providing what the plants need. Reducing the decaying/dissolving organics is the best thing you could do as long as your not stripping the tank of what the plants need.


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## naturelady (Dec 14, 2009)

Well, the concern with the water changes is the dissolved CO2 in the water. I've read some about this on Tom Barr's site. It was an older article, however. Perhaps he has changed his idea on it since then?

I've always been somewhat ambivalent about the idea, because it seemed to make sense for the plants, but probably not so great for the livestock.

seuadr, thanks for sharing your experience. Maybe some day my tank will stabilize a bit better...


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## houseofcards (Mar 21, 2009)

naturelady said:


> Well, the concern with the water changes is the dissolved CO2 in the water. I've read some about this on Tom Barr's site. It was an older article, however. Perhaps he has changed his idea on it since then?
> ..


Why would co2 cause algae? If the added co2 fuels plant grow then you just have to make sure your dosing the tank, other than that their is NOTHING more beneficial then a water change, It's great for the fish and keeping algae away. It also gives you more flexibility with light and other parameters.


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## naturelady (Dec 14, 2009)

Sorry. I am not explaining very well. The issue is not CO2, per se. The issue is constantly changing CO2 levels. When the tank consistently has a low level of CO2, the plants adapt to it. When you do a water change, you are introducing water with a high level of dissolved CO2, thus the CO2 level increases drastically. Therefore, the water changes cause constantly changing levels of CO2. The thing that plants like best is consistency. Algae can adapt to the changing levels of CO2 more quickly than can plants, therefore, doing the water changes gives the algae an advantage relative to the plants.

Of course, this is only applicable to no-CO2 setups.

Well, that's the theory, as best as I understand it, anyhow. Does that make more sense? So the idea behind no water changes is to keep the level of CO2 stable, albeit low, because plants will do better in those stable conditions.

The thing I am wondering is how people keep fish health in that kind of setup. I have found that very challenging.


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## m00se (Jan 8, 2011)

http://buddendo.home.xs4all.nl/aquarium/redfield_eng.htm


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## houseofcards (Mar 21, 2009)

No I do understand what your are saying about the change in co2 levels, but it's really a crock. The benefit of removing organics from the tank during a water change far away any slight increase in co2 from tap water. Most here change 50% of their water weekly, what do you think happens to the co2 levels in the tanks? What about those that turn their co2 off at night and the tank doesn't recover optimum co2 levels till afternoon? I've always made large weekly water on my non-co2 setups and they are pristine. The biggest risk of algae is too much light and too much dissolved organics.


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## FriendsNotFood (Sep 21, 2010)

I'd have to disagree with the dissolved organics and algae connection. Of my 5 non-CO2 tanks, the only one that doesn't have a spec of algae is the one that gets the least water changes. All my other tanks consistently get diatoms and green algae. Green algae especially I've noticed LOVES water changes. 

Now, all that said... my tank with the least amount of water changes also has nitrates through the roof and I suspect that hasn't been great for the fish in there. I know there are people on here who miraculously do no water changes AND have healthy fish but I haven't figured out that magic formula. So I'd say, if your goal is to have no algae, skip the water changes. If your goal is to have healthy fish, a weekly 25% water change is your friend.


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## naturelady (Dec 14, 2009)

m00se- I've heard of the Redfield ratio before. I always just thought it was the source of "too much phosphate causes algae" which I thought was a myth. Are you suggesting this isn't true? Or its more complicated than that? Or.... what?


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## houseofcards (Mar 21, 2009)

Are you dosing your tanks with NPK or relying on fish waste and food?


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## houseofcards (Mar 21, 2009)

FriendsNotFood said:


> I'd have to disagree with the dissolved organics and algae connection..


So are saying it doesn't matter how dirty your tank is with waste it won't have a bearing on how much algae you get.


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## Ashnic05 (Jan 7, 2013)

I am a firm believer in doing water changes. Removing fish waste and plant detritus is vital for a healthy aquarium. I would worry less about the varying levels of CO2 (because the difference in these levels is minute compared to the variance of levels these plants would normally experience in a natural environment) and more about the overall health of your tank.


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## FriendsNotFood (Sep 21, 2010)

houseofcards said:


> So are saying it doesn't matter how dirty your tank is with waste it won't have a bearing on how much algae you get.


Yup. Just in my experience. 
This is all anecdotal, but the way I originally got into this hobby years ago was by buying one of those "Frog-o-Spheres", a half gallon "tank" with bamboo and two dwarf frogs. I followed the horrible instructions that came with it and did a water change a few months after I bought it. Horrible, horrible, I know. I didn't know any better at the time ): 

Anyway, in the months before the water change, there was not a spec of algae in the tank. AFTER the water change, the glass became so green I decided to just ditch the tank and get a real one because there was no fighting the algae. Was the water filthy with organics before the water change? I would imagine. And yet there was no algae until tap water introduced fresh CO2 into the system. 

Beside my own personal experience, if algae results from excess nutrients, how are people able to dose EI? isn't the whole point of EI to flood the system with nutrients above and beyond what plants need?

Again, not arguing against water changes at all. It's MUCH much easier to keep a tank healthy with regular water changes than without.


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## plantbrain (Dec 15, 2003)

naturelady said:


> m00se- I've heard of the Redfield ratio before. I always just thought it was the source of "too much phosphate causes algae" which I thought was a myth. Are you suggesting this isn't true? Or its more complicated than that? Or.... what?


The problem with that article is the guy Charles does not know what the Redfield ration actually is, it's anatomic, not a molar mass ration.

Maybe 5 or more years ago, I sent him a discreet email telling him this and offered support for the error. He has never changed it. Never responded, so I have little issue ripping him when folks bring this up.

P is 32 g/mol, N is 14 g/mol so this produces a ratio error 220%.

So it's not 16:1, it's 7.2: N for MASS. Not that it matters much as far as growth and algae and plants in our case. Nor are the conclusions he reached in the article.

For non CO2 tanks, a good old pair of T8 light bulbs suits most tanks quite well. A good filter, generally I avoid HOB filters, prefer Wet/drys myself.
Canisters can be used though.

Balancing a non CO2 is not particularly hard if.....the fish load is relatively minimal at the start, you add mostly algae eaters, you add say 10-20% surface area with floating plants, you dose the sediment and/or the water column lightly. Plants will compete for light and CO2 VERY strongly, so some species, just are not going to make it, while some will grow like weeds.

Later, after the tank grows in more, then you can increase the fish load etc. Some use penny wort or Duckweed indexes to know when to dose, generally these tanks run lean on N, so KNO3 or more fish/feeding is required to keep the plant growth at that same pace.


While water changes did not cause issues for me, I also dosed after wards, but the point was I never needed to do water changes. 

You can approach this from Diana's view point and philosophy, which is pretty good and well argued, or use a water column approach I suggested some years ago, I guess there's a more or less old school lots of fish to supply the fert approach also.

If things get away from, do not fear the water change however.


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## houseofcards (Mar 21, 2009)

FriendsNotFood said:


> ...Beside my own personal experience, if algae results from excess nutrients, how are people able to dose EI? isn't the whole point of EI to flood the system with nutrients above and beyond what plants need?


So your comparing dosing NPK to the nutrients that are available in your tank form decaying waste? What do you think the difference is?


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## PeterN1986 (Jun 15, 2011)

FriendsNotFood said:


> I'd have to disagree with the dissolved organics and algae connection. Of my 5 non-CO2 tanks, the only one that doesn't have a spec of algae is the one that gets the least water changes. All my other tanks consistently get diatoms and green algae. Green algae especially I've noticed LOVES water changes.
> 
> Now, all that said... my tank with the least amount of water changes also has nitrates through the roof and I suspect that hasn't been great for the fish in there. I know there are people on here who miraculously do no water changes AND have healthy fish but I haven't figured out that magic formula. So I'd say, if your goal is to have no algae, skip the water changes. If your goal is to have healthy fish, a weekly 25% water change is your friend.


I agree here - I have done only ONE water change this year (2013) on my 20g tank. I have amanos and RCS's breaking down the fish poop and bigger pieces of debris. If you just leave it alone, it will be broken down by bacteria, who give off CO2 (negligible amounts at best probably). All I do is top off with tap water to replace the evap. I used to do water changes twice a month thinking that built-up ferts would be removed and thus slowing algae growth, but they still remained. Since I have stopped this year, the algae seems to run its course (or my oto ate them up  ) and I have very little algae now. 

As for nitrates, wouldn't the plants eat that up? I have a lot of anacharis stems in my tank, but I'm not sure if it hogs nitrates; I think it is know to hog up O2. I also have an Eheim 2215 running, which pretty big for just a 20g. My fish have been alive for 1.5 years now and survived two 6+ hour road trips in the back of my car.


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## plantbrain (Dec 15, 2003)

houseofcards said:


> So your comparing dosing NPK to the nutrients that are available in your tank form decaying waste? What do you think the difference is?


You can test this with old decayed plant trimmings.
Toss them into a well run tank without any prior issues etc.

You will have issues after this.

I've not seen this test fail. It might if someone only puts like 1-2 little stems in of 1/2 dead plants, but if you dump a say what might be 20% of the live biomass as rotten plants, it'll toast most plant aquariums.

Sort of goes back to the whole, = healthy plants= good stable place, hard for algae, if you load the system up with an overload of fish/plants to where they start to rot(limiting nutrients/rate of growth too fast etc), and if the plants do poorly= decay, algae etc.

Test works for non CO2 and CO2 enriched tanks also.

I've not found DOC to cause issues for planted non CO2 tanks though.
Decaying plants, yes, DOC, no, tannins, no etc.

Still, folks that are worried: activated carbon will remove the DOC's at least the larger molecules and tannins. Carbon will also remove any so caleld allelopathic chemicals. So if you think allelopathy plays a role, then adding carbon should induce an algae bloom, to date, I've not seen once such case/correlation.


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## plantbrain (Dec 15, 2003)

PeterN1986 said:


> I agree here - I have done only ONE water change this year (2013) on my 20g tank. I have amanos and RCS's breaking down the fish poop and bigger pieces of debris. If you just leave it alone, it will be broken down by bacteria, who give off CO2 (negligible amounts at best probably). All I do is top off with tap water to replace the evap. I used to do water changes twice a month thinking that built-up ferts would be removed and thus slowing algae growth, but they still remained. Since I have stopped this year, the algae seems to run its course (or my oto ate them up  ) and I have very little algae now.
> 
> As for nitrates, wouldn't the plants eat that up? I have a lot of anacharis stems in my tank, but I'm not sure if it hogs nitrates; I think it is know to hog up O2. I also have an Eheim 2215 running, which pretty big for just a 20g. My fish have been alive for 1.5 years now and survived two 6+ hour road trips in the back of my car.


I think shrimp are excellent shredders, they break down the larger particles so the micro inverts and bacteria can finish off the job easier. Plants will also remove most every other chemical in the water also.

Egeria is pretty tough and will grow great in non CO2 tanks.
the KH is also likely 0 in your tank BTW, this is when the algae start to die back and are not longer an issue, but it may be due to plants finally getting going and growing well/establishing.


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