Does Flourite increase tank GH?
I have been measuring water parameters as my new fresh water aquarium (20 gal.) has gone through cycling and population with plants and fish. I wanted good plant growth and invested in a bag of Flourite which I topped with previously used aquarium gravel. I washed both well before putting them in the new tank. The intial readings were GH - 9 and KH - 4. In two weeks the GH was up to 13 and dropped to 12 after I replace 10% of the tank's water. KH, pH, NH3, NO2 and NO3 are all stable and at reasonable values. The fish and plants are happy but I worry about the increasing general hardness. What is a reasonable GH range for tetras and corys? I suppose I could change out water more than once per week or even mix in some softer water, although I am about to try DIY CO2 and don't want the KH level to decrease much. Any thoughts?