Flatworms Maybe?
Hello everyone, just some food for thought. I have about 40 small colonies of Acans and some of mine were doing the same thing as you describe yours doing. I did all the dips and to no avail they went right back to same thing. Then my Hairy Mushroom of about 30 heads started looking really raggy, the heads looked like someone tore them in half with white noodles hanging out. I went from 30 heads down to 2 in less than 3 days time, then my Yuma's started doing the same thing. I tested everything and all parameters were right on. As I was sitting there staring at thousands of dollars of corals disentegrating, my daughter came by and said it looks like something is eating them, she went and got a big magnifying glass (6"x6") really strong one and handed it to me and low and behold after starring intently at one of my corals for a bit i saw something move and it was almost crystal clear but had a dot in the center of it appeared to be light brown. These things are so clear, that when they land on a coral then flatten out the coral under neath them show right through them, looks like a coral polyp only laying on the coral. These flatworms move fast too with an undalating movement. Well, I jumped up and made up 50 gallons of saltwater, removed all carbon turned off skimmer and UV filter and dosed the tank with 1 and 1/2 recommended dosage for my size tank. I sat there with the mag glass and watched as these things just floated up off of the corals then got sucked into my socks (literally hundreds of them) most range in size from a grain of rice to 2 grains of rice laid end to end. They were killed in seconds after adding salifert flatworm exit. After seeing them float up, I turned on skimmer and left the tank to sit like that for 6 hours, I had to empty skimmer cup about 6 times and my cup holds 6 cups of liquid. Then I changed water put new carbon and filter socks in and turned on UV filter. Later that night the corals were all puffed up and looking great.
I hope this helps.
