I don't have a fish tank, though; I have a reptitank, which comes in varying sizes similar along fish tanks. But yeah, basically, it is a glorified fish tank, just much more secure.

It seems odd to me to hear that you have so many snakes that strike. Almost everyone I know that owns balls, and has owned them for a long time, have barely gotten struck. But they usually don't do live prey for their pythons, and I know that that can factor into it.

Are you sure they aren't striking from anxiety of being in a small space? Or escaping because the enclosure is too small for them?