I hope someone can help me! My fantail has a swollen head and has done for some time, but recently I have noticed his eyes are gradually becoming hidden - soon he won't be able to see!
fantail_swollen_head3.jpg

He lives in a 30L filtered Biorb tank with a black moor which was bought at the same time but is a bit smaller, has one cloudy eye (always has) and is a bit shyer than the fantail.

I change the water/filter frequently and feed them a pinch of Tetra Goldfish Granules twice a day, some of which sinks to the bottom after a while so that the shy black moor can get some (the fantail is very greedy and will readily eat more food than the moor).

Neither of them have any problems swimming (like staying at the top/bottom or on one side).

Does anyone know what might be causing his head to swell up? Is he just overweight or does he have a swim bladder/bloat problem? How do I solve it?! Help!