I gave my GSC it's first taste of MEGA CROP! I mixed 1/4 tsp in a gallon of water. It didn't seem like it changed the pH of the water much/at all. I just have the shake tester. So if it was correct then the pH was 7-8ish. I know that's too high, so I added 5ml of pH down to the gallon. I don't have the slightest clue on how much to add to lower the pH to where I want.