So I decided to add some polyp coral into the tank. A day after the addition of the coral the fish start acting funny. they have been towards the bottom of the tank and not very active. They were eating fine. today, I come to find out since I'm out of state for a few days that the fish aren't eating at all and are getting shivers. Water tests and conditions were good with only nitrates being at 20ppm before I left. And all this started after addition of corals. I have a yellow tang, 2 clowns, 2 domino damsels and 3 blue damsels. I'm really hoping I don't return home to an empty tank. I'm fairly new to the hobby and this is an issue I don't know where to start going with to resolve. I'm thinking a possible toxin from corals??