Tropical Fish Keeping - Aquarium fish care and resources

Tropical Fish Keeping - Aquarium fish care and resources (
-   Beginner Freshwater Aquarium (
-   -   CO2 system & Airstones (

TED45 01-16-2011 10:14 AM

CO2 system & Airstones
I've heard that running a co2 system and an airstone together defeats the purpose of the co2 system. Is that correct?

cbirk 01-16-2011 10:49 AM

From my understanding the issue comes from the O2 from the airstone breaking the surface tension of the water and allowing the CO2 to escape into the atmosphere. I have heard that getting an airstone, or some form of bubbler that releases very small bubbles will reduce the amount of CO2 lost.

I however do not use CO2 in my tank, so best to let someone else chime in as well.

Byron 01-16-2011 01:53 PM

The purpose in adding CO2 is to get more carbon dioxide into the water, presumably to increase plant growth or sometimes to lower the pH (it does this notwithstanding). Any device that causes surface disturbance or excessive water movement increases the exchange of gasses at the surface, by expelling CO2 faster and bringing oxygen in faster. So in this regard, the two systems are working at cross purposes.

Assuming your use of CO2 is for plant growth, this can only help during the daylight since plants do not photosynthesize during darkness. Therefore, CO2 diffusion is usually turned off during darkness, otherwise it is just wasted and may cause a serious depletion of oxygen. At the same time, those with heavily planted tanks sometimes suggest running an airstone at night to ensure sufficient oxygen. This is only necessary in tanks with CO2 diffusion during the day.


redchigh 01-16-2011 01:56 PM

If you use CO2 (at moderate levels), most of the time there's no need for an airstone at night. Your fish will let you know.

I don't use CO2, but this is what my friends have said when I asked them.

All times are GMT -5. The time now is 09:47 AM.

Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
User Alert System provided by Advanced User Tagging (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

For the best viewing experience please update your browser to Google Chrome