nemo wrote:

Before adding the fluorite, my tank water had the following parameters: kH =
3, gH = 3, pH = 7.8
After changing the substrate, I was measuring the following params: kH 1,
gH = 1-2, pH = 7.0

When you changed the tank over, your KH went from 3 to less than 1, and your GH
went from 3 to 1-2. You are asking whether Flourite caused this change. Nope!

Tell us about your old gravel. It sounds like there was a calcium (GH) &
carbonate (KH) source in it, perhaps calcium carbonate, AKA lime. This could be
in the form of shell fragments, sandstone, or a variety of other rock types.

I had to increase the kH of the water to stabilize the pH. But is my 4.5 dkH
target too elevated? How about gH, should I continue targeting 3 dH?

3GH and 3KH is a nice target.


I currently use DIY CO2 injection through an air stone. Unfortunately, I
can't achieve 10 ppm because of the mixing produced by my Dynaflo 3 power
filter (350gph!!). But that'll be replaced in the near future by a canister
filter with a spray bar.

The spray bar will cause as many problems as your Dynaflo, unless you aim it
below the water line. When injecting CO2 the objective is to minimize surface
agitation. I've got my spray bar vertical in the tank, creating a flow across
the back. The fish love to swim in it, and the surface barely moves. Other
people put them horizontal at the back, pointing down or back at the glass.