corals dying and dont understand why

[Paul B]

Randy is correct it was a toxin as it always is when corals die overnight. Nitrate, phosphate, or anything else easily tested in an aquarium will not cause corals to die overnight.
Copper, chlorine or zinc will. I have lost corals over niight to all three causes.
Large doses of carbon in a canister is the fastest thing you could do if you don't have access to new clean water. Even if you could change all the water I would use carbon. I know all about what people say that it will not remove chemicals 100% but it will remove them enough to let corals live. Unfortunately, the toxins are already incorporated into tyhe corals and I think they are too far gone to save.
Good luck

 

[acrylic_300]

If that is all it is they will probably pull out of it. Dechlorinate it and run some activated carbon.

 

[hellssephiroth]

i finally got my new RO hooked up.... i ended up ordering a 7stage one from bulk reef supply. i never used a tds meter on my old one ... but i tested it with my new tds meter and it wasnt working very well, it was a cheapy one. so after redoing the piping in my house from.... copper.... to pvc this morning im waiting on my new tank to fill up. i threw out the old tank just incase. woot tds= 0 now! should i do a huge water change when i get home from work, assuming i have water, or should i do a few small ones over the week?