I always try to have twice as many cultures going as I will need to feed my frogs. This gives me at least a little room for an oops if mites were to happen. I also keep small crickets on hand for feeding them also and could switch to just crickets if a huge fly problem were to occur.

I was making new cultures every 7 days, but now I have 4 cultures booming with flies and 3 of them i haven't touched yet so I think I will switch to 10 - 14 days now and see how that goes lol.