My hot tub is connected to the pool filtration system - in the winter, I shut down the pool and leave the hot tub on - the filter and the booster pump i keep running when the temp get near freezing - my question is this - the spa is heated by a milivilt heater 150,000 btu/propane fired - is is ok to leave it about 50degrees, just above freezing or should the water be warmer - and the skimmer pump has 2 speeds - does it need to be on high when there is no one in the tub - i have to manually switch it to the lower speed, no problem. or does it have to run on high all the time.

Any help is appreciated as i am new to the spa game

Thank you

Mike

as long as the pump's running, the heater can be off. You can run low speed. But at some point you might want to heat the spa and low speed may not allow the pressure switch to open in the heater in order to operate the heater. In other words, you may need to go back to high speed to heat the spa/pool. good luck

Do what you want to do with this. The cost vs value question with regards to a faster heat up time is up to you. If you leave the spa at 50 degrees, it will take X time to heat up to a useable 100 or whatever your preference is.

But if you use the spa like once a week, then 40 degrees would probably be more appropriate and save you a lot of propane.

There is no exact science to this. Use your best judgement, in practice.

Agreed. If you use it a lot than I would maintain it closer to 70 or 80 so the heat up time is quicker and you don't miss your opportunities to use the tub. If you use it sparingly keep it as low as it can go without turning off to keep everything above freezing and you should be good to go.