Harlequin Looking Sickly

[Cossie1111]

I have this one harlequin, his not swimming with the shoal (just hangs out under some decor) not eating, and has this blackish "bruise" on his side.

His other tank mates are another 10 harlequins and 2 corydoras.

I did a water change yesterday to see if that helps but his still the same.

Please help!

 

[HayzH]

I have this one harlequin, his not swimming with the shoal (just hangs out under some decor) not eating, and has this blackish "bruise" on his side.

His other tank mates are another 10 harlequins and 2 corydoras.

I did a water change yesterday to see if that helps but his still the same.

Please help!

ok others will ask, so...

Tank water stats?, how long have you had the tank cycled? how often do you do a w/c? added any decor recently?, is heater working correctly? Any new additions recently?

 

[Cossie1111]

Tank cycled for about 2 weeks, wc once a week, no new additions, heater is fine.

Im away from my tank atm and cant get water stats