Hi I have a 700 gallon system that has been slowly cycled with fish and plants for the past 4 months. The system is light on fish, I could handle more but can't just add more bc I am raising trout. I am on city water but the water here is very hard, so a low pH has caught my attention. My pH is low, 6.0 with no sign of green, so it could be even lower. The fish and plants all look fine. This mor…