So maybe the filter is aerating the tank, removing CO2 and driving up the pH? I forgot about that. Another reason to remove that filter!! I think I will definately get rid of it and get something submersible. The plants are great! Maybe I can just use the filter to start up another tank. If I turn off that HOB filter, does the bacteria inside need the water circulation to survive or will it be okay for a few days? I may want to use it but probably not right away.
So I called the water supply company and found out that the tap water is soft and has a pH of 9.2 with a hardness of 1 grain per gallon (or 16 ppm). So it was okay that I added the oyster grit?
Is it necessary to do a water change too?
Thanks!
