# DIY CO2 for a 75 gallon tank



## izzy2 (Jul 20, 2008)

Even three 2l bottles of DIY (non pressurized) may not add alot co2 to a tank that size. What kind of filtrations on the tank. 

Co2 needs to have alot of contact time to be absorbed into the water. Running the tube into a canister filter or powerhead would increase the co2 saturation into the water.

Check valve stop the tank water from possibly flowing back into the bottles.


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## pufferfish (Aug 27, 2009)

I think its an Eheim 2236. That's another thing I don't understand. Do you really drill a hole into the tube coming out of your filter. That kinda sounds like a mess and I'm not really sure where to drill the hole or how to attach the tube. I've never used a powerhead either I looking into them now. Any type that would be good for this type of thing?


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## OverStocked (May 26, 2007)

DIY co2 is a waste on a 75g tank. You will have next to no impact... The inconsistencies will just cause more problems


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## Darkblade48 (Jan 4, 2008)

over_stocked said:


> DIY co2 is a waste on a 75g tank. You will have next to no impact... The inconsistencies will just cause more problems


+1.

Save yourself the grief and aggravation of having to change bottles endlessly and go with pressurized.


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## jmhart (Mar 14, 2008)

You _can_ do DIY CO2 on a 75g, people _have_ done it on bigger tanks, but it's a real PITA. 3 2L bottles won't do it. I used 3 2L on my 45g. You'll need many bottles and multiple points of injection, as well as really good water circulation.

CO2 is beneficial at any level, but the problem comes in when people _think_ they have a good level of co2 and start adding ferts and upping their lighting. If you're tank is low light and currently not having any algae issues, then the addition of whatever CO2 you can get from DIY CO2 will be beneficial.

But, if you're hoping to be able to move from low light to high light(or even increase your lighting at all) with DIY CO2 on a 75g, I advise against it. You'll have nothing but headache and problems.


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## pufferfish (Aug 27, 2009)

You all make a good argument. I should have started smaller. I guess I could spare at most another $200 on CO2. Does anyone know a good web site that I can piece one together? Also maybe a good reference to learn about pressurized systems so I can figure out what I need now and what I can add later?


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## Hoppy (Dec 24, 2005)

http://www.plantedtank.net/forums/diy/90710-diy-co2-regulator-how-info-lot.html should be interesting to you. It is the best post here, in my opinion, about how to assemble a CO2 regulator system.


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## Darkblade48 (Jan 4, 2008)

For additional information regarding how to set up your own pressurized CO2 system, check out the primer that I wrote (it is linked in my signature).


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## pufferfish (Aug 27, 2009)

Thank you all this information has helped a lot. I now understand how this process works. Now all I have to do is figure out which parts to use and how to but them cheaply.


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