just tested the heater, @ 1960 the heater kicks in but randomly shuts off, 1980rpm the heater stays on, so I think I'll start with 200RPM running at about 300watts.
Would this be a good starting point? Run @ 2k RPM in the AM between between 9am to noon, and again at 3000RPM 4pm to 7pm this would. This would be for the swim season where I'd like to have the heater heat up the pool.