ty. my Q was regaurding my "hostpital" tank that currently houses 1 of my newts, and 2 guppies. my g/f wnted to add a beta, we added it to the bigger tank instead. i wanted to add it to the other tank for some color, in an otherwise drab tank.When you breed bettas....If thats what you're talking about....When the fry start to be able to be freeswimming you need to remove the male as he will eat the babies. Male bettas will also eat other fishes fry, although im not so sure why you would be keeping a male betta in a breeding tank of other fishes.