I've tried this over on uk.rec.aquaria.misc but so far no answer.....

So, I have an adult Angelfish who had fungus.
Took him out of the main tank and treated with Interpet Anti fungus for a
week as per instructions.
Fungus cleared up fine, back to the main tank.

Two weeks later the fungus is back, just the angel no other fish, so I
treated him again.
This time it took two weeks.

Put him back in again, you guessed it, fungus.
Water test out OK (Ammonia 0, Nitrite 0, Nitrate 5, pH 7.0.
All the other fish (Corys, Clown Loaches, and more Angels are fine)
Tank is 240ltr.

Is there anything topical I can treat with, rather than water based
treatments ?
One book (Mary Bailey) suggests Gentian Violet....?

Peter