# DIY CO2 questions



## ADJAquariums (Jul 5, 2012)

Alright so... I need a little help, ive got airline tubing, check vaulve and bottles to house the yeast and such, the only question is how much of water and yeast do i need for my tank, it is a 40 gallon and im going to use an airstone as my diffuser, any help would be much apperciated, thanks.


----------



## Bryanmc1988 (Apr 3, 2012)

it would not be a good idea to use an airstone as a diffuser... it will dissolve and break up into small pieces all over your tank...


----------



## Rich Guano (Jan 19, 2012)

1/2 cup sugar and 1 teaspoon of yeast for every quart of water. Same as Koolaid! You should be fine with an Ocean spray 3 liter container filled 80% with the water. 

What works best for me is to add the sugar to the room temp water in the bottle and shake it till dissolved. gently sprinkle the yeast on top of the water and let it hydrate for 5 minutes. It will begin falling to the bottom and appear to foam on the surface. Then gently rotate the bottle so the yeast mixes with the water.


----------



## Hoppy (Dec 24, 2005)

DIY CO2 bottles produce a limited amount of CO2, so it really pays off to use a good method for diffusing it into the water. Otherwise, you will usually be very short on CO2. One efficient diffusing method is as described here: http://www.plantedtank.net/forums/showpost.php?p=1886010&postcount=2

I use 2 cups sugar, 1/2 tsp yeast, 1/2 tsp baking soda, in 2 liters of water. I dump in the yeast, the soda, then the sugar. Fill the bottle up just past where it necks down. Then I invert it with my thumb over the opening and shake it vigorously. Then, carry it over to the tank and connect it to the system. I use two 2L bottles, changing the solution in one every week. This is for a 65 gallon tank, and it gives me very noticeable improvement.


----------



## flc (Sep 10, 2012)

Hoppy said:


> One efficient diffusing method is as described here: http://www.plantedtank.net/forums/showpost.php?p=1886010&postcount=2



If you're going that route, why not just stick the tube outlet next to your canister intake? I'm sure others may feel differently, but as far as I'm concerned, the whole point of going DIY is the simplicity- fewer failure points and lower cost.


----------



## ADJAquariums (Jul 5, 2012)

Bryanmc1988 said:


> it would not be a good idea to use an airstone as a diffuser... it will dissolve and break up into small pieces all over your tank...


I know the consequences of the airstone so im thinking of shoving a piece of gravel in the end of the tubing and poke small holes around the tubing so it acts like an airstone without the actual air stone


----------



## ADJAquariums (Jul 5, 2012)

Hoppy said:


> DIY CO2 bottles produce a limited amount of CO2, so it really pays off to use a good method for diffusing it into the water. Otherwise, you will usually be very short on CO2. One efficient diffusing method is as described here: http://www.plantedtank.net/forums/showpost.php?p=1886010&postcount=2
> 
> I use 2 cups sugar, 1/2 tsp yeast, 1/2 tsp baking soda, in 2 liters of water. I dump in the yeast, the soda, then the sugar. Fill the bottle up just past where it necks down. Then I invert it with my thumb over the opening and shake it vigorously. Then, carry it over to the tank and connect it to the system. I use two 2L bottles, changing the solution in one every week. This is for a 65 gallon tank, and it gives me very noticeable improvement.


Thank you that was actually very helpful, im thinking of also going the 2 2L bottle route. thanks


----------



## wheatiesl337 (Mar 30, 2011)

I second the recommendation to use 2 bottles. This makes it infinitely easier to keep c02 levels stable.

I used a hagan mini filter to difuse. I got too much impeller cavitation when I injected straight into a cannister filter.


----------



## ADJAquariums (Jul 5, 2012)

Thank you all, hoping to get some good O'l Yeast today or tomorrow, thanks


----------



## Merth (Sep 9, 2012)

The diffusion method is the most annoying part. I'm currently attempting the syringe method until I decide to order a real one


----------



## Merth (Sep 9, 2012)

I have been very pleasantly surprised at how well the syringe method has been working so far!


----------



## P015 (Sep 26, 2012)

Hey ADJ, where did you buy the check valves for the DIY Co2? I know you can order them online, but was wondering if lowes or home depot might carry them? What is the Syringe method to diffusing it Merth?


----------



## Hoppy (Dec 24, 2005)

I got mine at Ebay. Just search there for Kynar Check Valve. These are very chemical resistant, so CO2 shouldn't bother them. Or, go to US Plastics and do the same search.


----------



## P015 (Sep 26, 2012)

http://www.usplastic.com/catalog/item.aspx?itemid=23369

Quite a few Kynar check valves, which size should I order Hoppy?


----------



## Merth (Sep 9, 2012)

here is a pic of syringe diffuser method:


----------



## Merth (Sep 9, 2012)

Its not exactly pretty but for free it works. I kept mine whole so I could use it as a bubble counter as well as diffuser. The syringe is available at any pharmacy I would think. Mine is a 10 ml version made for administering meds orally to babies. Good thing about these is no needle to deal with.


----------



## Hoppy (Dec 24, 2005)

P015 said:


> http://www.usplastic.com/catalog/item.aspx?itemid=23369
> 
> Quite a few Kynar check valves, which size should I order Hoppy?


1/8 inch is the best size for CO2 system tubing. I'm almost sure that's the size I use.


----------



## beedee (Jul 1, 2010)

Merth said:


> here is a pic of syringe diffuser method:


im using a syringe and a check valve as a bubble counter, works pretty good.

what did you stick in the end of the syringe to diffuse the co2?


----------



## Merth (Sep 9, 2012)

Im just using plain cotton balls currently til i can get to the store and get some cotton pads, stuffed inside a short piece of hose stuck into end of syringe


----------



## captainaqua (Feb 24, 2012)

hi gang. If I am allowing the CO2 into a cannister filter do I need to be concerned about this @ nighttime ? I have a 75 gallon planted tank running a 2217 E-heim cannister filter. Other than disconnecting the hose manually when the lights go out what are my choices?


----------



## ADJAquariums (Jul 5, 2012)

P015 said:


> Hey ADJ, where did you buy the check valves for the DIY Co2? I know you can order them online, but was wondering if lowes or home depot might carry them? What is the Syringe method to diffusing it Merth?


Sorry im so late here and for bringing this bad boy back up but i got mine at petsmart


----------



## Darkblade48 (Jan 4, 2008)

captainaqua said:


> hi gang. If I am allowing the CO2 into a cannister filter do I need to be concerned about this @ nighttime ? I have a 75 gallon planted tank running a 2217 E-heim cannister filter. Other than disconnecting the hose manually when the lights go out what are my choices?


The short answer is..."it depends"

If you have an extremely heavy plant load, the amount of CO2 they make at night could push it over the limit for fish (depends on their sensitivity, etc).

However, this problem is more common with pressurized CO2 and not DIY CO2. You did not mention how many bottles of DIY CO2 you are running, but it is doubtful that it will generate enough CO2 at night.

If you are concerned, you could put an air pump with airstone on a timer so that it comes on at night, but again, unless you are running a large number of bottles on your 75 gallon aquarium, you should be fine.


----------



## ADJAquariums (Jul 5, 2012)

Hmm it doesnt appear like my Co2 bottles are producing any CO2 unless i shake it rigourously for like 10 minutes and then its only like 5 minutes its going, im using 1/2 tsp of yeast and Baking soda, 2 cups of sugar, 2L of warm water and waiting an hour for the yeast to acctivate, anyuthing wrong here or is it my flaw? might try shortining the tubing from generator to my second bottle where the CO2 gets seperated from any bad "stuff that comes with it


----------



## Darkblade48 (Jan 4, 2008)

ADJAquariums said:


> Hmm it doesnt appear like my Co2 bottles are producing any CO2 unless i shake it rigourously for like 10 minutes and then its only like 5 minutes its going, im using 1/2 tsp of yeast and Baking soda, 2 cups of sugar, 2L of warm water and waiting an hour for the yeast to acctivate, anyuthing wrong here or is it my flaw? might try shortining the tubing from generator to my second bottle where the CO2 gets seperated from any bad "stuff that comes with it


How long has your DIY CO2 been going for? After 2-3 weeks, it is time to replace the mixture.


----------



## ADJAquariums (Jul 5, 2012)

I just started it yesterday, got no results from the reactor, restarted it today in hopes it was some simple error, 6 hours later absolutely nothing


----------



## Merth (Sep 9, 2012)

I use boiling water in bottle first then add sugar let this cool to warm...in meantime I mix a tsp of yeast with a cup of warm water and a pinch of sugar. When bottle is just warm add the mix, cap and shake a bit then hook it in. Starts producing in an hour or two depending how much water is in line that it has to force back into tank


----------



## Hoppy (Dec 24, 2005)

Usually when you see no CO2 production you have a CO2 leak, which could be at the bottle cap, or anywhere beyond that up to the bubble counter. The seal where the tube enters the bottle cap isn't good for much pressure, so a sticking or backwards check valve makes it leak there, or a sintered glass diffuser may take too much pressure to get gas flow through it, causing a back pressure and leak.


----------



## Tomas4444 (Nov 14, 2012)

Hoppy said:


> Usually when you see no CO2 production you have a CO2 leak, which could be at the bottle cap, or anywhere beyond that up to the bubble counter. The seal where the tube enters the bottle cap isn't good for much pressure, so a sticking or backwards check valve makes it leak there, or a sintered glass diffuser may take too much pressure to get gas flow through it, causing a back pressure and leak.


I think I may have this problem... I am using 3 two liter bottles with airline tubing pulled though the cap and sealed with silicone. I am getting a few bubbles through my counter (maybe 5 or 6 per min), but not as many as I would expect given 3 fresh bottles. Plus, if I shake the bottles I catch a whiff of fermentation (that putrid/overly sweet scent). Does anyone know a better way to seal 2 liter bottles? Would epoxy be a stronger seal?

And a totally unrelated question...
I have a 29 gallon moderately planted aquarium (same one as above) on which I am trying a DIY CO2 with a glass & ceramic diffuser. However, I use hang on back filters. I've read that the surface turbulence from these filters dissipates the CO2 from a DIY system so rapidly I may be wasting my time. Does anyone have a success story with HOB filters and DIY CO2? 

Thanks


----------



## Tomas4444 (Nov 14, 2012)

ADJAquariums said:


> Hmm it doesnt appear like my Co2 bottles are producing any CO2 unless i shake it rigourously for like 10 minutes and then its only like 5 minutes its going, im using 1/2 tsp of yeast and Baking soda, 2 cups of sugar, 2L of warm water and waiting an hour for the yeast to acctivate, anyuthing wrong here or is it my flaw? might try shortining the tubing from generator to my second bottle where the CO2 gets seperated from any bad "stuff that comes with it


I use the same mixture as you. If you ever need to test a bottle, fill a pot with warm water (~95 degrees) and let the bottle float in it (without tipping over) for a few minutes. Yeast metabolism goes absolutely gangbuster with a slight increase in temperature (that's why we use it make bread rise quickly in an oven). If you still don't see any bubbles after a good 20 minutes, the mix is used up or the bottle is leaking. I can get lots of bubbles using this method even when I freshly mix a batch and test it less than an hour later.


----------



## Tomas4444 (Nov 14, 2012)

Here is my set up. Let me know if the pic doesn't work...


----------



## Darkblade48 (Jan 4, 2008)

The picture works fine;

I would go over and check all the connections with some soapy water (drip the soapy water over the connections). If there are any bubbles that you can see forming, then you will know there is a leak.


----------



## james1542 (Sep 8, 2011)

Yea sounds like you have a leak. The best way I've found to seal the caps is to drill a small hole, get some rigid plastic tubing that the airline will fit over (either rigid tubing, or you could mutilate a barbed 3 way). Put the fitting in the hole, and surround it with hot glue on both the inside and outside of the cap. You can even pull it through the hole a bit to draw in the glue. Just don't get too crazy on the inside of the cap or it wont thread down. Also make sure your using an intermediate bottle in line(full of water) to scrub the air, otherwise you'll get some funky stuff growing in your tank... I like running a mininmum of 2 bottles, and I like the ~1 gallon juice jugs (the kind with the built in handle). 

As for diffusion, one idea I've used before: a collection bell. doesn't have to be fancy, it can be difficult to keep it from flipping over when full of gas, the surface area exposed to the water is more important than the volume and if you can get some current past it you'll get great diffusion. Right now I'm using a chopstick diffuser(free) with a collection bell collar threaded on to the CO2 airline- made out of a clear plastic lid about 1" in diameter. It's got my drop checker in the green zone, in a tank with poor flow on the opposite corner of a 20L.


----------



## captainaqua (Feb 24, 2012)

Thanks for the input. I am only running 1 bottle. I have been using the redsea turbo co2 biosystem and the waterpump went bad so I just put the co2 output hose in the intake of my filter.


----------



## ADJAquariums (Jul 5, 2012)

Looks like i might have a leak as well but i lack a bubble counter, what should i do to create one of those?


----------



## P015 (Sep 26, 2012)

ADJAquariums said:


> Looks like i might have a leak as well but i lack a bubble counter, what should i do to create one of those?


Are you going to use a separator bottle? (one that has the lining from the 2 liter bottles connected to it, and this separator bottle connects to the actual tank)

I'm still trying to figure the exact specifics out, but it looks like in the seperator bottle, there is water in it and the air lining from the 2 liters goes into it. This will create bubbles in the water and can double as a bubble counter.

see pic in link 
http://www.plantedtank.net/forums/showthread.php?t=152916


----------



## ADJAquariums (Jul 5, 2012)

P015 said:


> Are you going to use a separator bottle? (one that has the lining from the 2 liter bottles connected to it, and this separator bottle connects to the actual tank)
> 
> I'm still trying to figure the exact specifics out, but it looks like in the seperator bottle, there is water in it and the air lining from the 2 liters goes into it. This will create bubbles in the water and can double as a bubble counter.
> 
> ...


Thats what im currently doing on my generator, looks like it is actually producing CO2 and its just leaking


----------



## ADJAquariums (Jul 5, 2012)

So i fixed my problem, definatley was a leak, now the only thing is whenever i have it on it starts to gas my fish, first i notice that they all congregate at the top and start gulping air, thats when i take it out, i have an airstone going and it is producing soooooooo many bubbles, and all i have is one co2 reactor hooked up


----------



## Hoppy (Dec 24, 2005)

Here is where a drop checker will be extremely useful. I doubt that you get enough CO2 with that to gas the fish in that size tank. If you have a drop checker, set up correctly, and you are only getting blue green indicator solution, you can be sure you are not gassing the fish, so you will have the courage to increase the amount of CO2 you are adding, possibly by using a more efficient diffuser type. When I first started with CO2 I thought I was gassing my fish, too, but I wasn't anywhere near doing so, as I learned later.


----------



## Gamezawy (Apr 3, 2012)

1/2 tsp yeast, 1/2 tsp baking soda, in 2 liters of water 

so tsp = Table spoon or tea spoon ?


----------



## ADJAquariums (Jul 5, 2012)

Gamezawy said:


> 1/2 tsp yeast, 1/2 tsp baking soda, in 2 liters of water
> 
> so tsp = Table spoon or tea spoon ?


Teaspoon


----------



## ADJAquariums (Jul 5, 2012)

Hoppy said:


> Here is where a drop checker will be extremely useful. I doubt that you get enough CO2 with that to gas the fish in that size tank. If you have a drop checker, set up correctly, and you are only getting blue green indicator solution, you can be sure you are not gassing the fish, so you will have the courage to increase the amount of CO2 you are adding, possibly by using a more efficient diffuser type. When I first started with CO2 I thought I was gassing my fish, too, but I wasn't anywhere near doing so, as I learned later.


And as in drop checker do you mean an extra bottle filled with water where the hose from the bottle is submerged under the water then the tubing that goes into the tank goes into the top of the bottle and not all the way inato the water? because i have that setup running, i have heard that some of the Alcohol (i think its alcohol) from the actual mixture that is created will get into the tank if you dont have that setup

Also sorry for the long explanations, i just dont want to do it wrong, ive got wayyyyy to much money invested in the tanks livestock to take large risks


----------



## byork (Sep 28, 2012)

I have a DIY CO2 system currently set up on my heavily planted 60 gal. I rotate 3 bottles typically changing one out about every 2 weeks, meaning my formula is generating CO2 effectively for approximately 5 weeks. In the beginning I added the first bottle. I waited a week and added the second bottle. After my growth increased and my drop checker indicated that additional co2 was required I added the 3rd bottle to the rotation. My formula is... 
~1 tsp bakers yeast
2 cups sugar 
2 Tsp Molasses 
1 tsp baking soda
1/4 cup whey protein
3 drops dechlorinator (sp?)
For a 2 liter bottle, I have used this formula in 2 1 liter bottles on smaller systems with different rotational needs.

Yeast can be activated and produce CO2 both anaerobic and aerobic. We are trying to utilize the anaerobic process. So the less exposure to air the better. What I do is mix everything except the yeast in warm water. To ensure that everything is dissolved. I then add it to the bottle and add cold to Luke warm water to fill to a little below the top of the label. At that time I put the yeast with some Luke water. I squeeze the bottle so that the mixture raises to just below the top. Then I add the yeast water mix quickly screw the cap on the bottle, while it is still squeezed. Clap the tubing exiting the top until it is added to the system. You need to shake the bottle either before or after you connect it to the system, while still squeezed. This will produce a surge of CO2 which will more than expand the bottle. 

Diffusing can be effectively achieved by placing the end of the CO2 tubing in a large glass applesauce jar and propping it between the side of the aquarium and the outlet of a power head. You can use a smaller jar if necessary. The jar may have to be angled so that no bubbles escape. I am currently using a ISTA max reactor which I purchased online for $10. I have it on the out going side of my canister right before my spray bar. It works great! 

I have aeration on a timer turning on 30 min before the lights go out and turning off 30 mins before they come on. The CO2 runs continuously. 

Sorry to be so lengthy, and there are a million ways that are all right. This is just what works for me.


----------



## Hoppy (Dec 24, 2005)

ADJAquariums said:


> And as in drop checker do you mean an extra bottle filled with water where the hose from the bottle is submerged under the water then the tubing that goes into the tank goes into the top of the bottle and not all the way inato the water? because i have that setup running, i have heard that some of the Alcohol (i think its alcohol) from the actual mixture that is created will get into the tank if you dont have that setup
> 
> Also sorry for the long explanations, i just dont want to do it wrong, ive got wayyyyy to much money invested in the tanks livestock to take large risks


http://www.instructables.com/id/CO2-Drop-checker/
http://www.ukaps.org/drop-checker.htm


----------



## ADJAquariums (Jul 5, 2012)

Hoppy said:


> http://www.instructables.com/id/CO2-Drop-checker/
> http://www.ukaps.org/drop-checker.htm


Extremely helpful links! thanks, looks like i need to go out and buy some necessary parts for the checker


----------



## ADJAquariums (Jul 5, 2012)

Alright Bringing this Bad Boy back for a Third time, again help is needed. I have decided to start this up again. And i want to do it Right. Last time it just didn't go well so i just sort of quit. The first thing i would like to know is what is one of the best options for a DIY Diffuser? I don't want anything rediculously complicated but something that works well. I have contimplated hooking up the Airline tubing to one of my HOB filters and diffusing it that way.


----------



## Darkblade48 (Jan 4, 2008)

ADJAquariums said:


> Alright Bringing this Bad Boy back for a Third time, again help is needed. I have decided to start this up again. And i want to do it Right. Last time it just didn't go well so i just sort of quit. The first thing i would like to know is what is one of the best options for a DIY Diffuser? I don't want anything rediculously complicated but something that works well. I have contimplated hooking up the Airline tubing to one of my HOB filters and diffusing it that way.


A cigarette filter or disposable (wooden) chopstick is said to work wonders.


----------



## ADJAquariums (Jul 5, 2012)

Darkblade48 said:


> A cigarette filter or disposable (wooden) chopstick is said to work wonders.


Really? i never thought cigarette filters would actually have a use! however my parents might question why theres a cigarette filter in my tank, and how i got it :icon_roll. I think i will go the chopstick route. how should i do that?


----------



## Sugardaddy1979 (Jan 16, 2012)

That would work. Or you could just hook it to a ceramic diffuser or a limewood airstone,


----------



## Darkblade48 (Jan 4, 2008)

ADJAquariums said:


> Really? i never thought cigarette filters would actually have a use! however my parents might question why theres a cigarette filter in my tank, and how i got it :icon_roll. I think i will go the chopstick route. how should i do that?


Just break off a little bit of the chopstick and shove it into the airline tubing.


----------



## ADJAquariums (Jul 5, 2012)

Darkblade48 said:


> Just break off a little bit of the chopstick and shove it into the airline tubing.


I still don't get how that works. doesn't the pressure end up building and "shoot" the chopstick out the end?


----------



## discgo (Jan 21, 2013)

ADJAquariums said:


> I still don't get how that works. doesn't the pressure end up building and "shoot" the chopstick out the end?


No, the pressure ends up building and shooting out the opposite end of it in tiny bubbles.


----------



## ADJAquariums (Jul 5, 2012)

discgo said:


> No, the pressure ends up building and shooting out the opposite end of it in tiny bubbles.


 Ohh i get it now, thanks!


----------



## ADJAquariums (Jul 5, 2012)

I'm Back! with more questions too... I FINALLY have time to do what i want with my tank, so i'm thinking about actually doing CO2 right now, i have checked with my local chinese place and they said i Have to be in store to get the chopsticks and they wont do it on delievery, i have no clue why.

I can do an HOB setup, i could do a canister setup, what do you guys think would be the best here? im interested in doing the HOB setup but im not adversed to any ideas you guys/gals have.


----------



## Darkblade48 (Jan 4, 2008)

If you don't mind the additional cost, go for a canister. It will be quieter, and with an adjustable filter return, you won't have to worry about CO2 off gassing as much.


----------



## kingjombeejoe (Feb 17, 2013)

I agree, go with a canister if you can. There is a lot more options with canisters for co2 if you ever decide to purchase some kind of diffuser or reactor.


----------



## gSTiTcH (Feb 21, 2013)

kingjombeejoe said:


> I agree, go with a canister if you can. There is a lot more options with canisters for co2 if you ever decide to purchase some kind of diffuser or reactor.


Or make a reactor. ..


----------



## ADJAquariums (Jul 5, 2012)

Since i already have a canister (fluval 206) can i use that? may seem a bit of a basic question but i dont know... Anyways wheres the best place to start when doing that? put it into the intake and let it go through the canister?


----------



## Darkblade48 (Jan 4, 2008)

ADJAquariums said:


> Since i already have a canister (fluval 206) can i use that? may seem a bit of a basic question but i dont know... Anyways wheres the best place to start when doing that? put it into the intake and let it go through the canister?


You can use the Fluval filter.

For a reactor, it is best to put it on the filter return side, so that detritus does not accumulate within the reactor.


----------



## byork (Sep 28, 2012)

ISTA reactors are cheap and work really well IMO. You may have to change the tubing on the fluval if you are using the black stuff they come with.


----------



## ADJAquariums (Jul 5, 2012)

Ok, With the reactor setup, what is probably the best design you guys/gals have seen/used? i want something that i can build but im not truely adverse to purchasing one i guess, If i want to do it right it could come down to that. Im not the biggest fan of the soda bottles due to aesthetic reasons but i cuess i can somehow hide it, possibly within my stand


----------

