I treat my rotifier culture pretty bad sometimes, forget to feed.. forget to harvest etc.
They seem to be pretty stable for me
but generaly, you want to harvest regularly and make sure you feed every day but only enough so the culture is clear by the next time you feed.
Also, once a month I tear down my culture, strain it with a coffee filter (not the paper ones) and get the large ditritus out and clean out the bottle then strain it back into the cleaned out bottle. Some people recommend bleaching the bottle etc etc. but I do not do that.. also some people do not recommend a good scrubbing either because it may create a mini cycle and crash the culture.
Anyways, find a pattern that works for you. Run two cultures so you have a back up if one crashes.
btw, I just use the algae paste