If possible I don't want to use the ph up chemicals from the pet store. Anyways, I need to increase my pc to atleast 7.0 Out of the tap it's 7.2 but in my tank it's 6.2 for some reason. I tried a 20% water change but it didn't budge from 6.2 yesterday. All I have in my tank in the 200watt heater, a filter I took from another tank, sand (playsand) on the bottom of the tank, and ofcourse fish. My ammonia is 0, so is the nitrites. Any help would be awesome.