betas

Question
my grand daughter has 2 males in a 2 gallon tank with a little filter going.

on the sides of the tank it looks like slime drop all over.  I took the fish out, cleaned the tank & gravel then added new water and put the fish back in. The fish seem fine.
Any idea what this could be?
We have a water filter for my big tank, so I use this water to change the beta water.
thanks for you help

Answer
Roberta,                                                     When you house bettas together they can drop their slime coats from stress. I think that is your problem. Put one in your large tank. If there are alot of plants and they can find their territory they are fine with other fish. As long as they are semi aggressive. .... Good Luck, Tina