We need to move our Oscar from a 55 gallon to a 125 gallon tank. The GH
in the current tank is too high (12-13), the Ph is ok (7.2) and the Kh
is low (3). The Gh
of our tap water is much lower (about 6) so if we use that to fill the new tank, even if we use most of the old water, will the change in Gh
harm the fish? Any advice welcome!