# aquasoil buffering capacity



## treepimp (Apr 13, 2006)

I have a tank that I set up recently with ADA aquasoil, and was wondering if using a drop checker is the only sure way to figure out my CO2 concentration.
I've read that because aquasoil buffers the water, the KH/ph tables are no use.


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## eklikewhoa (Jul 24, 2006)

Yes, using the drop checker with a known Kh water is the only way to accurately measure co2 content.


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## Avalon (Mar 7, 2005)

Or, you could use the plants/algae as an indicator. Typically, every tank has tiny bits of BBA. Keeping enough CO2 will keep it that way. As pH shifts up given a steady input of CO2, these tiny bits of BBA will turn into tiny tufts, and grow from there. It's pretty easy to use CO2 when first using AS, as the KH will drop to 0 in all but the hardest waters, and getting enough CO2 into the tank is rather easy. However, for reasons I'm unsure of, when AS stops buffering the water (about 3 months or so after initial use), your KH will rise. Mine seems to rise to 5-6 dKH (from 0) if I don't change any water. I use 100% RO water (7.0 pH and 0 dKH), and have nothing that will buffer my water, but the KH will rise slightly.

To put it another way, there is a correlation between pH and KH, and the higher the KH, the more CO2 it takes to achieve a certain pH--one that's plant friendly/algae unfriendly. The "chart" is a poor method of determining CO2 levels. While I'm unfamiliar with using drop checkers, I have found over the years that plants/algae never lie. So, using the subtle powers of observation coupled with the ability to make small changes based on those observations, I think you'll find the success you're looking for!


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## treepimp (Apr 13, 2006)

Thanks for the help. Got a drop checker on the way. It's my first experience with aquasoil. My first tank I used the ph/kh chart on with much sucess. Never had any problems plants always pearled great and little to no algae. With my new tank though, I have to keep the ph around 6.2 to get any pearling. My kh at the moment is 4.5 which according to the ph/kh chart my co2 would be enough to kill anything. My fish and shrimp seem happy (no gasping for air) and my plants are pearling. I was just a little worried about the amount of co2 actually in the tank.


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