Hello,
I have 4 male guppies (and a snail) in a 13g cycled freshwater tank. One gup (Leroy) has been picking on another (Frankie). Frankie is normally timid, but these past couple days, he's been hiding and only coming out for food. Yesterday I saw his tail had been nipped. This morning it was shredded! I watched them for almost twenty minutes and finally I saw Leroy chasing Frankie. I put Frankie in a quarantine tank, but otherwise that's all I've done about the situation. Frankie is the only one Leroy picks on. Everyone else gets along fine with each other.
1. How long until Frankie's fins heal?
2. What else should I do for Frankie?
3. What should I do about Leroy?
4. Any other suggestions?
Thanks. I'm new to being an aquarist and I love my fish; I really want them all to be happy.

UPDATE:
OH NO!!!! I just saw Leroy FLASHING!!!

Okay, so this means he has the
ICH, which means they all do, which means I should turn the temp up on their tank, right? (I'm gathering this from what I've been obsessively reading these past few days....) What temp should I put it on and what else should I do?