All the fish in my sig were in the 180 litre tank but I'm having to move things about a bit as they're not getting on any more.
Before I got the 2nd tank, one guppy hovered around the bottom of the tank for about a day. He stayed in one spot but flapped his side fins away as if he was swimming, also his mouth was opening and closing pretty much all the time. After that he started hiding or sitting on top of leaves, he wasn't feeding either. After a couple of days he died dispite showing no signs of injury or illness other than his behaviour.
At the time I checked the water parameters (ammonia, nitrite, nitrate, ph, gh, kh) and all were perfect (except gh and kh which were better than the local tapwater conditions), I treated the tank with melafix and moved the sick guppy into a breeding trap in case he was being bullied or something. All the other fish in the tank were in good condition. As far as I could tell there were no reasons for it at all so I just put it down to a random illness.
Since then several guppies have been nipped by a dwarf gourami (I assume), as has the neon dwarf gourami, so I've put the injured fish into the new tank to recover.
The other day I noticed another guppy hanging around in one spot of the tank, later he was sitting on a leaf just like the previous fish although this time he was not displaying the odd 'swimming on the spot' or mouth behaviour. I moved him to the treatment tank in case he was being stressed by the gouramis but he doesn't seem to have improved much, although he has kept eating throughout.
When I put him in the new tank, one of the guppies may have picked on him a bit, not sure though. He would swim up and bump into him, they'd both jerk about and swim off, but he'd go right back to him again. Is this just because he's sick and an easy target? I put him in the breeding trap for a day, let him out but he went right to the edge of hovered there until the same guppy swam up and nudged him over and over again, so back in the breeding trap he went.
Do you have any ideas of what it could be or what I should check for or do? It's a bit discouraging when fish die for no apparent reason.
Really sorry for the essay
Before I got the 2nd tank, one guppy hovered around the bottom of the tank for about a day. He stayed in one spot but flapped his side fins away as if he was swimming, also his mouth was opening and closing pretty much all the time. After that he started hiding or sitting on top of leaves, he wasn't feeding either. After a couple of days he died dispite showing no signs of injury or illness other than his behaviour.
At the time I checked the water parameters (ammonia, nitrite, nitrate, ph, gh, kh) and all were perfect (except gh and kh which were better than the local tapwater conditions), I treated the tank with melafix and moved the sick guppy into a breeding trap in case he was being bullied or something. All the other fish in the tank were in good condition. As far as I could tell there were no reasons for it at all so I just put it down to a random illness.
Since then several guppies have been nipped by a dwarf gourami (I assume), as has the neon dwarf gourami, so I've put the injured fish into the new tank to recover.
The other day I noticed another guppy hanging around in one spot of the tank, later he was sitting on a leaf just like the previous fish although this time he was not displaying the odd 'swimming on the spot' or mouth behaviour. I moved him to the treatment tank in case he was being stressed by the gouramis but he doesn't seem to have improved much, although he has kept eating throughout.
When I put him in the new tank, one of the guppies may have picked on him a bit, not sure though. He would swim up and bump into him, they'd both jerk about and swim off, but he'd go right back to him again. Is this just because he's sick and an easy target? I put him in the breeding trap for a day, let him out but he went right to the edge of hovered there until the same guppy swam up and nudged him over and over again, so back in the breeding trap he went.
Do you have any ideas of what it could be or what I should check for or do? It's a bit discouraging when fish die for no apparent reason.
Really sorry for the essay
It is discouraging when the fish shows no signs of diseases and I experinced that problem a little too often. Does the guppy appear to by gasping? Is he swimming normally, besides his odd behavior? 
