I recently discovered the importance of KH for buffering purposes. I could not figure out why my 7.0-ish water from the tap was becoming closer to 6.0 in the aquarium.
Once I received the test strips from this site in the mail, I discovered the KH in my tank is 0. (ph around 6, 0 nitrite, 10-20 nitrate) It comes out of the faucet at around 25 KH. However, I feel the ph swings are stressing my community tank out. Especially my Oscar.
Some suggest alkaline/acid buffer, some suggest things like crushed coral. Any ideas? I'd prefer not to have too high of a PH since it is a community tank. Something natural and low maintenance would be terrific.
The 125 gallon tank consists of 1 oscar, 5 silver dollars, and 1 featherfin catfish. 2 FX6 and 1 Tidal 110. The sand is Stoney River and is supposed to be PH neutral. I also have a pothos plant in hydration leca.