First things first- my tank is a 29 gal, planted with gravel. I have a bunch of female "feeder" guppies, 2 male platies (two more in quarantine) 1 male swordtail, 2 danios, 1 neon tetra, 1 cory cat, and a clown pleco. (Before anyone mentions it-yes I know there is a problem with stocking since many of the fish need bigger schools, they are mostly lone survivors from me not being in town and leaving the care of the fish to others) I'm not putting in my parameters partly because I know they aren't perfect but mostly because literally- the ONLY fish affected are the guppies. The guppies just keep dropping like flies, I had a bit of a bacteria bloom because some dead ones were hidden in java moss. They don't really show symptoms they just die. I started treating with General Cure because some of them looked thin like they might have parasites. They all seem perfectly fine in the morning and then at night they are pretty quiet and at the surface, not gasping or anything just pretty listless. Some of the guppies have a good appetite, some don't have an appetite at all. Some of the old ones died, so have some of the youngest. Now this strain of guppies is horribly unhealthy. I got some from a pet store once and right off the bat a bunch died but that's to be expected with fish from a feeder tank. Then they did pretty well, most of the males at that time were fairly healthy but any since then do well until they're a month or so old and then stop eating, they chase food but spit it all out and they wither and die. A lot of the females get tumors (at least that's what I think they are) they get yellow spheres of something mostly inside, I've seen some in their peduncle, in their heads if you look at them from above, etc. I don't want the guppies to suffer but the ones that are dying are perfectly fine one day and dead the next, the bodies even look fine except for the fact that they're dead. Since I know these guppies have always had problems and *no other fish is sick in the slightest* I don't know how hard I should try to treat this, not to mention I wouldn't even know where to start really. Should I just let nature take it's course?