Gill swollen up like a balloon?

[ruecole]

I noticed this morning that one of my white cloud's has a gill swollen up like a balloon. It's whitish pink in colour and has absolutely nothing hanging off it. He's eating, he's swimming, etc. Just his gill is very, very swollen.

I think it's the same fish who I've treated three of four times before for a swollen gill. I've tried Melafix and General Cure and both have seemed to help--only to have, about a week or two later, it swell back up again. This is the worst it's been, though.

Any thoughts on what his ailment might be and what I can do to fix him?

Thanks!

Rue

[Crusty]

The actual gill or behind it?

[ruecole]

I'm not entirely sure. His gill plate is forced open and there's a large balloon-like whitish-pink mass sticking out. At first it was just a small bit sticking out and I thought it might be anchor worms, but after each treatment (during which it shrinks down until it seems like it's gone) it comes back within a few weeks worse than before.

He doesn't seem to be suffering (he eats, swims, acts like a typical fish), but I'd still like to cure him if I can!

Rue

[Squidman]

Does it appear red? Is it scratching it against surfaces?