Hello all! Need help. I just started my tank I put live plants, dragon rock, and Driftwood in a 9 gallon fluval flex. I'm doing test and my ph is about 6.6-6.8 my kh is little too none and my gh is high. I live in San Diego and the water here is hard. I was thinking about putting crush coral in my filter media but I'm worried that it will raise gh. What should I do.