buffered water affect on CO2 measurement?

[eea876]

Hello everyone... looking for some input.

Over the last few weeks I have been adding baking soda to my water to increase the level of KH in my 30 gallon tank. By doing this I am raising the KH in my tank from around 3 to around 9 degrees.

In this tank I using DIY CO2. I have been using my pH level with my KH level to estimate the level of CO2 in the water. Will the charts I am using (http://www.thekrib.com/Plants/CO2/kh-ph-co2-chart.html) still be usable for me?

Thanks in advance for you help.

 

[TPIRman]

Because the buffer in baking soda is bicarbonate, the KH/pH/CO2 chart is still valid for your tank. The chart assumes that the only buffer in the water is carbonate (rather than phosphates or certain organics), so the change created by baking soda doesn't break the KH/pH/CO2 relationship.

Out of curiousity, why you are increasing the KH so much? A KH of 3 is borderline, but not terrible to start with.

HTH.

 

[eea876]

3 degrees was not enough to prevent a pH crash that devestated my 30 gallon. I going with the better safe than sorry and upped the KH. Increasing KH is my attempt to ensure pH stability.

So far so good on that front .... pH doesn't budge...