# DIY C02 reactor or diffuser?



## Blaxicanlatino

I built a DIY C02 generator (with the yeast and 2liter coke bottle and stuff) and i hooked it up to an airstone and placed the airstone under the filter intake (so the bubbles would get chopped up by the filter propeller) but I noticed that the airstone is getting a clear film around it. SO i want to remove the airstone and find another way to mix the the co2 better into the tank. How do you make a cheap diffuser/reactor? thanks you


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## JHK30

what is the clear film?:question:


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## Blaxicanlatino

no clue, i read from many posts and sites that this clear film is common.


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## JHK30

whats it caused by?


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## Blaxicanlatino

its unknown what causes it


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## ThalesthePearsei

I don't know much about the white film on the aristone, but I wouldn't reccommed you use your filter to chop up the bubbles. The high acidic content of the Co2 bubbles will cause excess wear and tear on your filter and can do some damage. 
I have a DIY Co2 on my 3g planted. For a diffuser, I just used a bottle cap from one my my distilled gallon jugs and put a hole in the middle to insert the are tube for the air stone to go underneath the cap. I glued rocks on the outside and on the edge of the bottle cap to disguise it in the tank and weigh it down. Then, when the glue was dry, I put it in the tank and dug the diffuser as deep into the substrate as posssible, and even put rocks over it. I have had great success with this, as the Co2 bubbles are trapped inside of the tank for at least 10-15 minutes before they finally make their way up and out of the diifuser. My plants are doing well. 

Does anyone know exactly how long the mixture in the bottle lasts before you have to make a whole new mix. I have read 10-15 days but I am not sure if this is a correct estimate.


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## swingshift

it depends on the temperature of the yeast mix. with the cold weather, i've had my heat on, and my co2 produces pretty heavy for about 8 days, then dies down to barely anything. keeping the mix at a low temp will give you more staying power, i've found.
and make sure you're using fresh yeast. 
i use 2 cups sugar, 1 tsp active dry bakers yeast, 1 small pinch baking soda.


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## ThalesthePearsei

baking soda? Why do you add baking soda? I have never heard of that.


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## KevinG

1) I beleive your statement that the "high acidic content of the Co2 bubbles" is wrong. The real issue is more of a mechanical one. The "bubbles" and cause cavitation. This is to say bubbles around the impellor of your pump. This could upset the balance and damage your pump. Now that being said, CO2 injection will cause a ph flucuation but it would not make your water so acidic as to damage your equipment.

2) CO2 injection is a process od gas exchange. Your cap simply doesnt have enough surface area to give you a good exchange.

See this link for some really good info on DIY CO2
DIY CO2 System for Planted Aquarium

Didnt mean to rain on your parade, just trying to help.


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## chally567

Get a powerhead and a container and a bio ball. Put a hole in the container for the powerhead. then put in bio ball and you have a reactor.


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## ThalesthePearsei

a quote from the website you suggessted: "some of the components in the impellor use rubber fittings, which could be broken down over time by the high concentrations of CO2 gas and carbonic acids present."

....so I wasnt wrong after all

my diffuser I described is identical as the bell diffuser on the website. II just have gravel on top of it so its not an eyesore. So I don't think you understood how I described it before


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## Blaxicanlatino

i did the cap idea only, i modified it a bit: i took a water bottle and cut off the top with the cap. that way, the bubbles have a large surface area to collect before it fills over the edges at the bottom. The bubbles will stay in the water for a long time this way. i coutned about 45 min.


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## FuzzAz

I use 2 3-litre . bottles, both bottles are hooked up and I change one bottle a week alternating between the two and that gives me a consistent output. Each bottle on its own last 2 weeks but output drops after a few days. I use a ceramic diffuser found on eBay for under $10. There is no need for any needle valve or regulator because it wont make enough CO2 to do any damage. This setup kept my 36 g. at a constant 10ppm and made a noticeable difference. It actually is fairly cost effective if you buy the sugar from sams club @ $20 for 50#, that’s a year’s worth. But I got very tired of the routine and recently dropped a wad of dough on a pressurized system.


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## Blaxicanlatino

I agree, im actually thinking of saving up for one. But the DIY still works well.


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## FuzzAz

I'm pretty and resourceful. Still it cost me about $200 to put together a pressurized system. About $120 of that was for a 10# filled tank of CO2. The rest was for a used regulator, 3 needle valves, and various fittings. The tank could have been cheaper if I had found a used one, but I live in a small town and none came up over the past several weeks so I paid full price from the welding shop. Just to give you an idea.


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## KevinG

My apologies. Clearly we were not communicating well about the "bottle cap from one my my distilled gallon jugs". As for the cavitations of the pump impellor, your risk most definitely from mechanical failure. All parts wear and fail over time but just ask anyone who has had a small leak in the pump suction how fast a little air can ruin a pump. Best of luck with you endeavors. Keep up the good dialog, that’s how we learn.


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## Evoclimber86

Try this ebay sale. This is what i have and it makes realy fine bubbles. Works almost to good. I had to take it out beacuse my plants were geting out of controle. As for the bottle dont use plastic. Use a good thick glass bottle like Smirnoff or Jack Janiels bottle. They stand up right and dont flop on there side like a plastic bottle would after pressure builds. 

S8 CO2 Diffusion - Aquarium Defuser Gas Pressure Tank - eBay (item 250399104896 end time Apr-29-09 20:40:25 PDT)


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## FuzzAz

Evoclimber86 said:


> Try this ebay sale. This is what i have and it makes realy fine bubbles. Works almost to good. I had to take it out beacuse my plants were geting out of controle. As for the bottle dont use plastic. Use a good thick glass bottle like Smirnoff or Jack Janiels bottle. They stand up right and dont flop on there side like a plastic bottle would after pressure builds.
> 
> S8 CO2 Diffusion - Aquarium Defuser Gas Pressure Tank - eBay (item 250399104896 end time Apr-29-09 20:40:25 PDT)


 
Have to disagree with the glass bottle, use 2 or 3 liter pop bottles. I learned the hard way, once when I was a teenager I tried to make wine in my bedroom using a glass jar. Fermenting (which is exactly what a CO2 generator does) can make enough pressure to explode a glass bottle and that’s just unsafe. A CO2 generator shouldn’t ever make that much pressure if its working properly but the potential is there and a plastic pop bottle is built to withstand pressure and if it does fail it wont explode as violently. I have bought probably about 15 of those diffusers on eBay. They are way less expensive but only about half of them work well due to inconstancies in the ceramic disks.


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## Evoclimber86

FuzzAz said:


> Have to disagree with the glass bottle, use 2 or 3 liter pop bottles. I learned the hard way, once when I was a teenager I tried to make wine in my bedroom using a glass jar. Fermenting (which is exactly what a CO2 generator does) can make enough pressure to explode a glass bottle and that’s just unsafe. A CO2 generator shouldn’t ever make that much pressure if its working properly but the potential is there and a plastic pop bottle is built to withstand pressure and if it does fail it wont explode as violently. I have bought probably about 15 of those diffusers on eBay. They are way less expensive but only about half of them work well due to inconstancies in the ceramic disks.


Ive used glass bottles for years now and never had a problem. The pressure isnt going to be enough to break 1/8 inch thick glass. the top is going to blow off first if anything. As for the pressure if your forcing CO2 through a very fine ceramic disk 2 feet under water your going to have some pressure.


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## kumartks999

*co2 diffusor*

hi,

i have a simple version of a UG tube capped at both ends, the bottom is used to bubble up the co2. the top cap is slightly enlarged to accomodate the output of a small powerhead. 

the cap on the top is blocked using a sponge so that the bubbles cannot escape.

the bubbles meet the powerhead output and the result is that they are burst into fine ones. the downward / upward clash ensures that the co2 stays longer and since it is a powerhead output, mixing is better managed in the aquarium. will post the image soon. 

u can also add a bio ball for better effect and experiment with the flow so that the co2 is completely dissolved.


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## 55gCichlid

*Co2 Generator, Filter and Diffuser*

I just setup two 2 liter bottles (sugar & yeast), ran into a 20oz bottle w/ gravel (filter bottle), ran thru volcano extended tube w/ hollow flex bubble cord inside 20oz bottle (suction cuped to wall) w/ house fountain pump (suction cuped to wall) ran into bottle w/ Co2. Anything else? Good setup?
:-D


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## 55gCichlid

I took a flexible air cord, pullled the hook up off removed inside flex cord, super glued hook up back on, attached it to Co2 hose (from two 2 liters) ran it into a plastic bottle w/ bottom cut off, took the flex cord (from inside air cord) and wrapped a suction cup to the bottle and attached to inside wall. Then I took a pump from a house fountain and ran it from inside wall into bottom of 20oz bottle and it seems to be working well.


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## Goody

GOnna be trying a diy co2 soon my self


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## flett044

kevin g - just say c02 in essence is carbonic acid, so it is slowly dissolving the filter parts. you are wrong. if you dont believe me google it.


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## BILLSSHO

Blaxicanlatino said:


> I built a DIY C02 generator (with the yeast and 2liter coke bottle and stuff) and i hooked it up to an airstone and placed the airstone under the filter intake (so the bubbles would get chopped up by the filter propeller) but I noticed that the airstone is getting a clear film around it. SO i want to remove the airstone and find another way to mix the the co2 better into the tank. How do you make a cheap diffuser/reactor? thanks you


Believe it or not, plain cotton makes a great diffuser. I took a small filter media bag and put a small cotton ball in it from an old medicine bottle (about the diameter of a quarter.) Next, I ran the airline to the middle of the cotton ball. Secured it with a small rock on the floor of my tank. This produced very fine bubbles, and very *LOW* pressure is required for a steady flow unlike ceramic and other diffusers. Perhaps best of all, the cotton is easy to replace and costs nothing since we all have some lying around the house somewhere.


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## BILLSSHO

Remember that "surface tension" (or movement) is a key factor in losing CO2 to the atmosphere. That's why I like internal filters vs. outside filters for growing plants. My tanks have very low surface tension (you do need some movement but not much.)


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