hang on filter and overhead filter are different.

I am using hang on filter in my planted tank. They doing fine with my tetra. If you are using over head filter. You might need to tight the sponge on the sucker to prevent the tetra suck by the power head.

btw, i keeping male and female betta with my tetra. My bettas are not fight with any tetra. coz they do feel like lost in space when u keeping them in bigger tank with other fishes.