Originally Posted by DamselnDistress
is this ich?
dips are effective at removing the trophonts attached to the fish but will do nothing to treat the tank. The "attached" stage is only one of three so you are basically only paying attention to 1/3 of the problem.
the fish in the display tank and treating them with hyposalinity or copperin a sepeate tank is the best course of action. Once all the fish are being treated, the display tank can then be left fallow for 4+ weeks to ensure the parasites die out naturally without the need for further treatments.
It also looks like it has a secondary bacterial/fungal infection so a gram negative anti-biotic would be good as well.