Just checked pH of my water with a new test kit. It's between 6.4 and 6.6
I was using a meter with a probe, earlier. By results from the water test, I would assume that the pH of the medium is even lower.
What is the best way to adjust the water's pH? How about aquarium pH adjusting tablets. One tablet per 10 gallons is the recommendation. That is to maintain 6.8 - 7.2 for aquarium.