Upside Down But Still Breathing

[ice(kat)]

barcoo grunter is upside down but still breathing i dont know wat to do help plzzzzz

 

[WILDER]

Not enough to go on, size of tank in gallons or litres, how many fish and which type, water stats in ammonia,nitrite,nitrate, and ph.
Has the fish bloated up and is he unable to maintain his balance, once a fish is upside down not good news, it can be swim bladder and once it has progressed hard to cure.