Join Date: Jun 2003
Location: Springfield, Illinois, USA
I would let the pH drop a little more. The ideal CO2 concentration is about 15ppm. Your fish are all well-suited to more acidic water. Just be careful to keep your CO2 below 25 ppm. At that level, O2 levels drop to a point where it becomes harmful to your fish.
With a KH of 5, your ideal pH would be 6.9 to 7.0.