Definitely take all the fish and healthy thin gs out. Even if you put them in a rubbermaid tote thats large, with some live rock and an air bubbler with new saltwater.
Dose tank with amquel for ammonia and heavy metals, dose new quarantine too with it.
Water change. Carbon. Good luck! Sorry this happened.
If your not comfy doing this take the fish to the lfs temporarily
Definitely not a stray voltage. You cannot electrocute a salt water fish. Stray voltage can cause irritation over time but that is obviously not what is happening.
Good luck finding your problem and I hope things look better this morning!
Im going with "cuke nuke". Need to find it if you can, and remove it. What type of sea cucumber was it? Its probably a waiting game now, as the toxins have been released. Other than that I agree with doing the biggest WC's you can get away with as well as fresh carbon. Perhaps removing the fish like mentioned too.
Thanks for the kind words. I'm leaning towards the cucumber nuking the tank.....still can't find him....it was a red and black. The only two fish I can see are the clowns...and they are still alive. The Tangs are dead and suspect everyone else is as well.....don't see them. I'll wait until lights are on to start pulling them out.
I changed out the carbon last night....maybe I'll do that again this morning. In a couple hours I have another 50 gallons of new saltwater to change out as well. Also running the skimmer wet.