Cup Coral, Turbinaria - Algae issues

[Apostle]

I have a Cup Coral, Turbinaria which I purchsed 3 months ago. It's only the third coral i've purchased. The coral is in good health and all my params are fine except for phosphates. Just got to wait till pay day so I can afford some new phosphate remover.

Due to the elevated phospate level I have diatoms on part of the coral and want to know how to get it off without damaging the coral. How much pressure could I apply (if any) to try wiping it off. And what should I wipe it with, just my finger?

I've tried holding it directly in front of the pump but this wont shift it.

Any ideas?

Thanks

[MIKE NY]

if algae is growing on it then that area of tissue is dead...I use an old toothbrush or frag off the dead area.