Well I've had my tank for about 8 months now and most everything has been going good. I leave to go out of state for a month and left my aquarium at home for my family to watch after.

I come back and all my fish are alive, surprisingly, but it seems like a guppy has dropsy and fin rot :( He is pineconed out pretty bad and the top half of his tail is pretty much missing with white and red outlined on it. No one told me about it while I was away because they didn't want me to worry but I fear it may be too late for this little guy.

He stays at the surface all the time, even when I change my water. He used to play in the incoming stream but still stayed over in the corner. I did a 50% change when I got back because apparently my family didn't do a change in the last month.

I've been home a few hours and fed him and he ate but is still lethargic and not moving out of the top corner. I do not have a hospital tank and considering putting him out of his suffering.. Any suggestions?

20 gallon long
2 guppy
5 neon tetra
5 ghost shrimp
planted
7.6 pH, 0 ammonia, 0 nitrites, ~20-40ppm nitrates