Hi,
Sorry to hear you lost your fish.
I would always use Melafix to cure whitespot as it's a natural fish remedy which is safe to use. raise the temp to 30 degrees (slowly) and add a 1 1/2 recommended dose.
This might help for next time.
Cheers,
Moritz
hey, the tank has been cleared of fish for about 4 days in which time i did a big dose of white spot remedy, then last night i did about a 90% water change. when do you think would be safe to put the survivors back in?