I have a 20 gallon tank that has some issues, plus it is overcrowded. I plan to replace it with a larger tank, much better filtration, and fresh substrate. My problem is, the water parameters on the old tank are a bit odd and I don't know if the fish will need special acclimation. This is what I am dealing with:
old tank: 20 gallon, 4 years old, pressurized CO2 and Excel, flourite/laterite/gravel mix, GH 14, KH 10, Ph 7.2.
new tank: 29 gallon, flourite black, pressurized CO2, probably Excel. The readings on my other four tanks are: GH 3, KH 3-4.5, Ph 6.6-6.8.
I used salt every week for the first two years ( I had mollies). I have been doing big water changes weekly (40%) for the past year and watching the KH, and it hasn't budged. I assume the problem is in the substrate. Will the change from hard to soft water stress the fish? (four rosy barbs, three odessa barbs, and two pepper cories) If I use water from the old tank, maybe 50%, could I bring the problem with it (whatever the problem is)? Also, the tank is full of crypts which I plan to transplant... how will that go? And the big question, was it the salt that made the GH and KH so high? Or is there something else I am missing?