We have 10 Mickey Mouse Platties, 5 yellow tail guppies, 1 blue, split tail guppy, 1 sunburst platty, 2 blk mollies, a handful of assorted tetras and 4 algae eaters.
The guppies keep harassing the platties. They chase them and nip at them. Some of the platty's fins are ragged. I have read other posts and I do not think that there is worm problem that is causing the nipping. The guppies seem to leave all the other fish alone. Should I find a new home for the guppies?

We have a 125 gallon tank, total fish about 35, good on nitrate/ammonia levels; water may be a little alkaline, but still in safe zone.

I have a tank full of mickeys and fancy-tailed guppies. The female guppies don't bother with the mickeys, but the male guppies do try to "mate" with them because to them it looks like a big fat female guppie in "heat". Guppies watch the females for swollen and darkened bellies to mate (which with them is ALWAYS), so you can see where they get confused. I've never had to separate them though, so I guess it depends on your tank situation.