Sick Rummynose? - Help please

[Daren100]

Hi,

We have 6 rummynose tetras and one of those looks not too well.

He looks a lot smaller than the others and his tail is pretty much together and not fanned out, if you know what I mean. He seems to spend a lot of time near the top of the tank with his tail higher than his head, facing down at about 45 degrees.
He looks to have a couple of white spots on him but its quite hard to tell due to their colour.

All the other rummynoses seem fine as do *** the other fish in the tank.

Any suggestions?
Thanks

 

[SWerner13]

what are your water parameters? how long have you had the fish? how long has your tank been set up? what other fish are in the tank? how big is your tank?

 

[Daren100]

Water is fine. No nitrite, PH at 7.5, no other problems.
The fish are about a month old but the tank is about 4 months old and not had any previous problems.
There are 4 barbs, 4 harlequin rasbora, 4 glass catfish, 4 khuli loaches, 4 clown loaches, 2 banded garas and a siamese algae eater.
The tank is 145 litres (30 or so gallons?) with a fair few plants.