| I would be worried about swings in temp. A constant environment is usually best. Regarding temperature, many hatcheries use colder temps to give the algae an edge over bacterial growth (or so I have been told). I know at higher temps many microalgae become inefficient in one or another cellular process and leak organics into the surrounding water which can become food for bacteria. There are not too many species (except thermophilic species) of microalgae that prefer 90F (32-33C) in many cases that is approaching lethal.
Regarding rotifers, temperature varies with strain and influences reproductive rate. Each strain has its optimum (S strain 28-35C, L types 18-25C; in general temps should be between 20-30C (68-86F) Hoff and Snell 4th ed. Plankton Culture Manual.
If possible I would recommend renovating closet space into a plankton production area or some other place where temps can be controlled somewhat...just a thought. | 
