Replace Single Speed Pump to Save Energy

Hi,

I'm trying to wrap my head around what I should do with my pool pump configuration on would appreciate any input. Here are the details:

50K gallon pool w/ integrated spa in Northern VA
Polaris 280 pool cleaner
Hydramatic pool cover that we keep closed whenever the pool is not in use
Autopilot SWG
Pool will be open from April through October

Current pumps:
Pentair 011018 IntelliFlo 3HP (we set this at 2100RPM to run the waterfall/stream feature when people are in the pool, that is currently its only use)
Pentair WFE-6 Whisperflo 1.5HP (this is currently our primary pool filter pump, it is one speed and is set to run from 5am-11pm every day)

We have energy monitoring on all circuits in our house. The pool house subpanel is currently using about 41kWh per day of electricity, which is a substantial portion of our total electric usage. I believe almost all of this usage is driven by the filter pump. Our electric cost is $0.12/kWh.

This is a brand new pool, so all of the equipment is at the beginning of its service life.

What is the best / most cost effective way to improve the energy efficiency of this setup? Some options I was considering were swapping out the motor on the WFE-6 for a two speed or swapping the InteliFlo in as the primary pool pump and trying to find a single speed pump that will generate the right flow rate for the stream / waterfall feature to replace it.

I would appreciate any input.