I have an a serious question that possibly needs a quick answer! Inside my fluval Flora I am using the stratum that came with the setup and I also have a piece of driftwood that is releasing tannins. I did a 20% water change last night. I have a filter with foam and Seachem Purigen as filter media. My PH this morning was at 6.5 and had a KH of 53.7-71.6 (API KH test is a little hard to distinguish colors) so that put my co2 levels at 33.02 roughly. About 2 hours later I checked it all again and my parameters are PH of 6.0 and a KH of 53.7 giving me a co2 level of 90! Is this correct?? I am housing a bamboo shrimp and a red eyed puffer. Am I suffocating them??
Thank you all for the help!