Constipation is a very common cause of swim bladder problems, so I think the best thing you could do for him is fast him for a day or two and then feed him the insides of a pea. Do you have a means of quarantining him? It'd be easier to keep the other fish from stealing his food and make sure that he doesn't eat algae or whatnot in the main tank. How long has he been this way? Have you seen him go to the bathroom? What, how much, and how often have you been feeding the fish? I'm unfamiliar with fish diseases, so I can't say if it resembles one or not. I hope he does okay.

Yes a steamed cooked squashed pea will work wonders if it is constipation.

What have you been feeding the small tank (size please)

Keith

Thanks Kitty / Keith

will try the pea - I think you may both be right.. I hadnt noticed him "going to the bathroom" and watched him all day yesterday (i keep them at work).. Nada!! lol .. and this morning he is going, and seems to be swimming much better as well!

Will bring a pea to work tomorrow to make sure things are ticking along!

The tank is actually a very large vase, about 6+ litres, with a proper filter and pump on it.

:)

That vase is miles too small for those fish 2 guppies would be a max.
Where in OZ are you?

Keith

im new but 6 liters seems big enough for 3 smallish fish. What is the diameter of the vase? (Diameter is the distance from on edge to the other going throught he middle)
The suface area of the water has a lot to do with the amount of fish you can have, because the bubbles from the filter or airater (spelling) dont dissolve much oxygen into the water, but the ripple from when it hits the surface disolves the most oxygen.

6 litres = only about 1 1/2 gallons of water.

I'm afraid that is too small for those fish. I'd only keep one guppy or platy in it, myself. How long have they been in there? Do you test the water? Even if the readings are coming out okay, I'd still try to get like a 5g for them.