Well to start with you need to get the fish in a bare bottom tank, Ie no lr
and no sand or cc
. Then start treating for ick, either by copper (tangs can't handle this very well so be careful), or lower the sg
using a refractometer down to 1.009.
The second thing to do is empty the display, the copper if used "full strength" has probally killed the lr
so you have to start over. Unless 3 applies
Three, If you had and inverts they are probally dead (if not then maybe you got lucky), get a copper test kit and start measuring levels, start changing out the water in what might be considered "massive" water changes, I would change out 100% to start with and then do a 10 to 15 % daily, Copper is deadly to most inverts and the stuff that lives on the lr
and in the ls
After a week of water changes I would check the copper levels and if "not detectable" I would go buy a few snails and place them in the tank. This would tell you if your lr
is shot. If it is then you would need to go back to option 2, empty the tank, rinse the lr
, and ls
completly and let dry and start over again.