I've read a number of threads and have a question about Ph levels. I was told by LPS that I should keep it at 7.0. I typically test around 7.2-7.5 following a water change. I treat the water to lower it to 7.0. I have 38-gal. freshwater, planted aquarium with tetras, Mickey mouse, and a Molly. Is the chemical harmful? Should I just let the fish adjust which I've read in a couple of threads?