I woke up this morning to a dead royal gamma which was perfectly fine yesterday and active. I have two yellow tail clownfish, a gobe fire fish and a lont tentacle anemone. All water parameters are good and nothing is wrong, same with salinity. The tank is a 20 gallon long and has great filtration and flow. I also have some diatoms but I have it under control and phosguard has always removed it on new tanks. However, I looked at one of the clownfish and I noticed his fins are deteriorating. The fire fish tail also seems to be deteriorating. They look like strings now! I don’t know what to do, please help!