Hello. I have a 75 gallon display tank and a 30 gallon refugium. There is good flow through the system and I am currently using an aquac remora skimmer. I have 4 damsel fish, had 5 small hermits (don't know how many left), 2 turbo snails, and an emerald crab. Plenty of live rock and I have oolitic sand for substrate. The tank is about 3 months old. So here's the problem. Everything is checking out as far as chemicals go. pH = 8.2, ammonia, nitrite = 0, nitrate < 10, salinity = 1.025. I had clear water until I put some algae in the refugium. I bought some red mangroves, chaeto, and gracilaria. The mangroves and chaeto are doing fine but the gracilaria started dying (white/clear spots). At about this time it started getting cloudy, kind of brownish. Checked the levels, everythings fine. Thought it was an algae bloom but water changes aren't helping. Found that the gacilaria was dying so removed it but that didn't do a thing. Now I notice that my skimmer isn't producing any skimmate. I'm at a loss here. I don't know what's going on or how to fix it. This morning I woke up to find a dead fish so I think this is more serious than just an algae bloom. Any help would be greatly appreciated.