I will attach a photo, I have a 32.5 Fluval Flex. With the Marine 3.0 which I know isn’t the best but thought would do for now with soft corals, I have 4 zoas in different locations and all seem to be doing fine except this one which has gone from a light green to a brownish, everything else is doing great and my nitrates phosphates and pH seem to be doing good, what could the issue be?