I got my money on a PH issue and I'm willing to bet I know what caused it.
One question for you, but also plz tell us the ph and how often you been checking it, when you were doing the setup of your equipment did you soak your Hydrotron in PH balanced water until the PH of the water didnt change? Meaning PH water to 5.8. Soak Hydrotron. Wait couple hours or so and check PH. If it is off by more than .1 or so drain water and refill with fresh PH'd water. Continue this process until water that is soaking Tron is within .1 of what you PH'd it to. My example of 5.8 would allow 5.7 or 5.9.

Did I win?? :wtf: