Check one of the stickies in here about making a CO2
drop checker. For a little bit of work and a couple bucks you can have a relatively accurate value of CO2
in the tank.
The problem with the pH/KH
relationship is that its only accurate in a perfect system. The truth is we have a lot of dissolved solids and chemicals in that water that can change/buffer the pH. So when you do the pH/KH
chart from Chuck, you might be wayyyyy off.
The idea of the drop checker is to have a reference solution in the tank that you know is a set KH
, [b]with no actual contact to the tank water. No fish food, ferts, poo, or other chemicals can get into this solution. This creates that perfect system that the pH/KH
chart is meant to describe, and gives you a very good estimation of CO2