Best way to treat goldfish fungus?

[jeanius]

hi all,

i've recently converted my tropical tank to a coldwater tank and started off with 6 fantail goldfish. all is well however 2 of the blackmoores have developed fungus on their bodies.
just wondering what would be the best way of treating this as i've never had fungus problems before, only ever white spot. am i better off:

1) buying a specific anti-fungus treatment or will my aquatopia white spot eliminator work as well? it contains 37mg/mL Formaldehyde, 0.32mg/mL Malachite Green

2) should i treat just the 2 fish or treat the entire tank (all 6 fish)?

3) when i discovered the fungus yesterday i started using melafix just to be on the safe side, is it worthwhile continuing the melafix treatment for the next 7 days or not really?

thanks in advance!

[jeanius]

oh yeah i have a 90 litre tank if that makes any difference

[Woodsy]

Swap over to Pimafix for fungus - it will be fine to use on top of your melafix, but a water change will be beneficial before adding it.