My Cichlid is swimming weird and might die

[sonicvortex]

I have a 3ish old Cichlid and he started swimming almost upwards, he seems to be eating but he can hardly can swim, he looks sad. I changed the water, the temperature and PH looks fine. I have other cichlids and a couple of plecos and they are all doing fine.They have a heater which keeps the temperature around 25 degrees, the only different things is that it has been really cold lately and the new water which had the same anti chlorine, waste control drops and the other fish seem to be normal. What could be the problem?

 

[TheCommunityCichlid]

Make sure your nitrates aren't to high. Otherwise he could have being bullied and sometimes fish just don't make it. Hope he pulls through.