Substrates
Black basalt sand is cheap in Hawaii but in a jar of 50/50 sand to RO water (7.0 initial pH) it raises the ph to 8.5. I am doing a high-tech tank with mineralized soil (my initial soil pH is 7.5). I would like to have pH in the range of 6.5-7.5 and am concerned about the sand. Thoughts? Not...