水草情迷

Have anyone used SERA CO2 indicator before? How accurate is it? Will it be affected by the KH value of the water? Or maybe it is just a pH indicator (just like we calculate the amount of CO@ b using the KH-pH chart)?

應該唔會關ph事......
kh 就有好大關係...co2 溶了多少落水就係影響kh value.

Chuah Siong Peng: my same suspicion too. u can test it by measuring water that has been acidify with for example, ph down additive, or peat filtered, but no co2 injected. if u can read high co2 in those water, then u know that at least it is not actually measuring co2.

Tam: actually more co2, lower ph, as co2 dissociates in water to form weak carbonic acid. kh affects the ph drop (due to injection of co2) by acting as a buffer. Assuming the same quantity of co2 is injected into the water, water with high kh will have less ph drop than water with low kh.