hmmm... i dunno... Well it turned out the little guy had fungus. He got it twice. I think he finally kicked it. Now he's has a veeery mild case of hexamita and is healing well. Yup, I had my betta with a platy in a 5 gallon for two months. They were fine for a while, but the betta randomly started chasing the platy and nipped it a bit. After one nip, I treated the tank with Melafix, and had to take out the filter cartridge. That caused bad water quality and the platy got dropsy and died. I haven't tried another tank mate since. I was thinking about an otto until I had to clean the tank out and boil all the rocks and stuff... all the algae went away. I was thinking about some tetras maybe, but I will wait a looooong time to be sure my betta is well.