CO2 vs Sponge airstone filter

[I swim with Discus]

Greetings Discusheads- I have a great planted tank, and I am considering a CO2 tank setup. The only problem is, along with my overhead filter, I use an additional sponge/airstone filter. Will the CO2 setup lose its benefits because of the airstone sending all the CO2 up, up and away? Has anyone used both successfully? Respectfully, I swim

[zamboniMan]

You just have to turn up the CO2 more. (If you get a 5 lb tank it'll still last 6 months to a year)

[Larry Bugg]

Your airstone will outgass the Co2.

[exv152]

Your airstone will outgass the Co2.

Definitely, the airstone will disperse the CO2 no matter how much you pump into the tank. There really isn't a need for an airstone if you have a rectangular tank with plenty of water surface movement.

[I swim with Discus]

That's why I clarified it because its a sponge filter w/ an air stone. It holds all the good bacteria, so its important to circulate it. Would this work though...I have the CO2 on during the day when the plants are synthesizing and then turn of the tank at night and the filter on? My concern is that I may have ph fluctuations-

[exv152]

Also long as your KH is at a good level, 3-6º the pH fluctuations will be minimal.

[Larry Bugg]

Yes, if you are running the Co2 during the day and the airstone at night, that will work fine. No need for the Co2 to run while the lights are off anyway, it is just wasted since the plants will not use it during that time. Most will tell you to set your timer up so the Co2 comes on 1/2 hour before the lights come on and go off 1/2 hour before they go off.

PH swings due to Co2 do not effect your fish. It is swings due to things like additives or as exv152 stated, your buffering that effect your fish. A large percentage of us that keep high light/Co2 tanks shut the Co2 off at night. With this the ph drops evertime the Co2 comes on and rises everting it goes off. The fish never know the difference. Here is a pretty good response to this from Tom Barr.

http://www.barrreport.com/co2-aquatic-plant-fertilization/3834-ph-swings-c02-danger-fish.html

[I swim with Discus]

Thanks Bug, Exv- You guys ROCK! My fish and plants thank you-