Marine velvet

The drop in salinity shouldn't hurt the fish. They can take it. The corals and other invertebrates are another thing. For the fish, I would suggest raising the salinity slowly (days). I'm not sure what to recommend for the inverts but slower is probably better than fast. You should be able to make most of your corrections with water changes. Have you tested alk, ca, mg? Whatever it is you can still correct with water changes. You can slowly bring up salinity by topping off with salt water instead of fresh water.

 

The salinity and the params are most likely responsible for the chain of events. I've never heard of any anemone living in that low of salinity. With params off like that it probably killed the nem and a low ph will also stress everything in the tank and with the nem rotting away it furthers the degradation of the water quality affecting all the inhabitants. Salinity hurting the fish was never a concern of mine. I would just use this as a lesson to keep track a little better or establish a different routine. DJ, I just lost a bunch of nice adult fish to brooklynella. I feel your frustration my friend. Like bill me said, water changes will definitely help and get you back on track. Just try and keep the fish as stress free as possible. Don't make to drastic of a change quickly though.

 

I would start by doing a decent size water change since you had a nem die in your tank and put in some fresh activated carbon. Feed the fish a healthy meal but dont over do it.