I'm sorry, but we all talk about rotifers crashing as if it had something to do with where you bought them. They crash for the same reason fish die, something they need is missing, not enough food (or too much), or bad water quality ....
I keep phyto, rotifers, bbs, and soon mysids, I have never had a crash. I deal with rotifers about avery 2-3 day, phyto once a week, and bbs as needed (I keep dwarf seahorses).
If your cultured phyto, rotifers or bbs crashed (dies) then you have a problemm, not the culture (except dieing of course).
Get Frank Hoffs book on culturing phytoplankton, and read the many pages about water quality, temp, ph, salinity, and most important, CLEANLINESS.
Since I said CLEANLINESS so loudly, I should say this:
Anything that is empty is cleaned, PERIOD. You don't rinse it, you don't put it in the dishwasher, you fill the sink with a good cleaning solution, you wash it, you rinse in a light solution of bleach, let it dry in the open air. And if there is something rough on the glass, you get some muratic acid from the pool store and wash the items with a dulited solution.
I guess this is why people use purchased phyto, culturing can be a big job, but if your gonna do it, do it right.
Good Luck landlord
