# DIY CO2 - not enough pressure for ceramic diffuser, too much for airstone. Options?



## tinselsnips (Oct 1, 2013)

I have a coke-bottle CO2 setup in my 29 gallon tall. When I initially set it up, I tried using a ceramic glass diffuser, but couldn't get any actual output from it - even physically squeezing the bottles, I couldn't get any bubbles out of the diffuser.

So I switched to an airstone, and I get a *ton* of flow out of it. So much so, in fact, that it all bubbles straight to the surface and gasses out.

My drop checker is currently bright blue, and I'm wondering what my options are to improve diffusion? I've read multiple posts from people who had no issues using DIY with a ceramic diffuser, and others saying it's impossible.

I find it odd that even when I physically squeezed the bottle, I got no flow out of the diffuser (it's not leaking out - I soaped the whole system, it gets to the point that I can't physically squeeze any farther, so there is definitely internal pressure). Is it possible it's defective? It's a $5 Ebay special, so I suppose that's possible, however when I submerge it, the water happily creeps *in* through the ceramic.

Can anyone offer some advice?


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## Silenced (Aug 20, 2012)

Instead of ceramic glass diffuser, try other cheap, simple diffuser (ceramic/plastic).
Or simplay setup another bottle or increase the size of bottle (i dont know what size is yours though..) to increase the overall output pressure.


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## asuran (Oct 12, 2007)

use power head as diffuser, it works very good for DIY CO2


tinselsnips said:


> I have a coke-bottle CO2 setup in my 29 gallon tall. When I initially set it up, I tried using a ceramic glass diffuser, but couldn't get any actual output from it - even physically squeezing the bottles, I couldn't get any bubbles out of the diffuser.
> 
> So I switched to an airstone, and I get a *ton* of flow out of it. So much so, in fact, that it all bubbles straight to the surface and gasses out.
> 
> ...


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## mnellis3023 (Aug 27, 2007)

powerhead or chop stick


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## awesometim1 (Oct 31, 2013)

Hagen mini Elite filter is also good


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## ShortGirl (Jul 17, 2013)

I built and use this in my 10g. http://diyfishkeepers.com/forum/showthread.php?8258-5-steps-DIY-CO2-Diffuser
Also you could examine and tweak your co2 recipe to get better pressure. 

Sent from my SCH-I535 using Tapatalk


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## Dobie Swift (Sep 21, 2013)

I have a 2-litre DIY CO2 generator. I have it hooked to this and get a substantial amount of micro bubbles flowing when I first mix the yeast and sugar. After about 2 weeks I have to start giving the bottle a shake every day and that gets me 1 more week.


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## tinselsnips (Oct 1, 2013)

Thanks for the input! I'm going to give the ceramic diffuser another shot, but if that doesn't work I'll try the chopstick and then go from there.

Edit: After some more Googling, I came upon this forum post which describes _exactly_ my issue. Maybe I just need more patience...


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## asuran (Oct 12, 2007)

you may try cig filter as well if you don't get enough pressure


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## Sunrise City Rider (Oct 26, 2013)

Use a power head. I used the Hagen mini filter but I switched to the Marineland 660r. I stuck the line in between the the sponge filter and the intake. The output is strong but I aim it to shoot through my plants in a way that doesn't uproot them. I placed the mini on the opposite end and the CO2 mist just ping pongs around the tank. I like the circulation it creates too. The Marineland 660r cost me under $20 and the mini was about $13.


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## asuran (Oct 12, 2007)

im using maxi-jet 400


Sunrise City Rider said:


> Use a power head. I used the Hagen mini filter but I switched to the Marineland 660r. I stuck the line in between the the sponge filter and the intake. The output is strong but I aim it to shoot through my plants in a way that doesn't uproot them. I placed the mini on the opposite end and the CO2 mist just ping pongs around the tank. I like the circulation it creates too. The Marineland 660r cost me under $20 and the mini was about $13.


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## TekWarren (Oct 6, 2013)

I was about ready to give up on my DIY setup, just not happy with lack of pressure and ran into same problems as you. My dad wanted to try the ista mix max and they are pretty cheap so he got me one also. I finally hooked it up as a last resort. I didn't really want to cut my canister line but it's easily replaceable. It's only been a few days but it seems to be working. I can see the co2 actually being mixed up in the water instead of just bubbles floating up and gassing off like in the tank. No air stones or diffusers to mess with.


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## tinselsnips (Oct 1, 2013)

Update! Apparently patience was the order of the day. After 24 hours, my ceramic diffuser is happily bubbling away! I know I waited at least a day the first time I tried, but that was with a single bottle and probably needed longer for the pressure to build.

For anyone who finds this through Google, the following is my working setup:
- 2x2-litre Coke bottles, with 2 cups sugar, 1/2tbsp baking soda, and 1/4tbsp "traditional" baking yeast. Add the sugar and baking soda, fill 2/3 of the way with like warm water, and shake until the sugar is dissolved. Then add the yeast, and DO NOT SHAKE. I don't know why, but I get much better flow if I just let the yeast sit on top.
- 1x1 litre coke bottle as a gas separator.
- 1x ceramic diffuser
- both large bottles connected to a t-joint, with check valves between the bottle and the joint. The t joint is then connected to the gas separator, with a needle valve between them. The gas separator is then connected to the diffuser, with another check valve. This setup lets me remove any of the bottles without de-pressurizing the system.

Thanks for the suggestions!


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## GoJoeGo (Feb 4, 2014)

It took me forever to figure out how to get mine working too. I needed more pressure as well. I am using five one-liter gator aid bottles, one as the bubbler and four to generate CO2. I put one cup of sugar in each bottle, about two cups of water and 1/2 tsp of yeast to get mine going the way it needed to be. It takes about four hours now to start putting bubbles into the tank.


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## Italionstallion888 (Jun 29, 2013)

Mine does fine with 2 coke 2l bottles. I get 3 weeks or so with them


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