# DIY CO2 diffusion question



## pogobbler (Jan 4, 2013)

I recently added a bunch of new plants to my 10 gallon (primarily) betta tank. I've got a Finnex FugeRay Planted+ light on the way and over the holidays I'm planning on cobbling together a DIY CO2 system, with the 2 liter bottles and all. As they're not expensive, I'm sure I'll just get a commercial diffuser for the DIY system, but I wanted some opinions on another idea I had. I filter the tank with a good sized sponge filter and was thinking that another option would be to run the airline from the CO2 system to the bottom and slightly up into the sponge filter, so the CO2 bubble would rise up through the sponge, presumably taking longer to rise to the top (such as with a ladder type diffuser) and perhaps also being broken into smaller bubbles, as well, which would help diffusion. So has anyone tried this or have any opinions on it?


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## coralbandit (Jul 29, 2012)

I'm thinking if the bubbles build up in sponge it will float(no good).Can't say for sure but it may have an effect on your beneficial bacteria also(lack of o2).
I would try a small pump with venturi nozzle and send the co2 through it.Most DIY co2 systems won't develope enough pressure to work with any factory made diffusers.
Here's a good small pump;Amazon.com: Rio Plus 50 Aqua Pump - 69 GPH: Pet Supplies
Otherwise I would see if you have enough pressure to even go through an airstone or allow co2 to enter water as deep as possible(longer contact time).


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## jrman83 (Jul 9, 2010)

If all you have is sponge filters I wouldn't try CO2. You need to dispense CO2 around the tank, the goal being evenly. If you don't do this, and sponge filters do not move the water around adequately, you can have areas in your tank with little to no CO2 and others with high potentially dangerous levels of CO2. 

Aside from that, DIY CO2 does not produce enough pressure to push standard diffusers. Not sure if the idea you mention will work.


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## foster (Sep 2, 2012)

I use small powerheads to disperse CO2 in my tanks. It works very well. Like mentioned previously, use one with a venturi inlet that feeds into the impeller. It will chop the CO2 up very fine, and send it throughout the tank fairly evenly.


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## James0816 (Jun 19, 2009)

The DIY method will build up plenty of pressure to use with most standard diffusers.

DIY CO2 Made Easy

I use a variety of ceramic diffusers in my DIY setups.

I would be curious to see how these setups work with a sponge filter.


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