Thanks so much for the follow-up.

I'm looking forward to seeing the end results!

Normally, you don't prime on low -- in fact I don't believe any of the pumps are capable of priming on low. In most applications where I've run 2 speed pumps, the pump runs on low 24/7, unless vacuuming, backwashing, or under heavy load.

If you want to be able to toggle the pump on and off, you have to start the pump on high, and then switch to low. Intermatic has some ganged timers that allow that. Another method is to install a high quality check valve within a few feet of the pump on the suction side, to prevent prime loss.

Something to keep in mind is that sand filter performance actually increases as flow rates decrease, so running the pump on low 24 hours uses less electricity than high for 8 hours AND filters better. Depending on your weather and debris loading (here, the June forecast is hot & humid with afternoon thundershowers dumping leaves and debris into your pool!), you may need high speed, say from 6 - 9 pm, to drag surface goop and leaves into the skimmer.