With a variable speed pump, it costs me less than $25 a month to filter the pool for 8 hours a day. I run it at 1400 RPM (which uses 186 watts) for 6 hours and another 1-2 hours with the pool monster at about 500 watts (using a straight through leaf basket to the pool monster saves about 150 Watts).
In the winter, our electric tends to hit tier 4 earlier, so that offsets the savings a bit on having to run the pump less, but it’s probably just south of $20 a month for power.
With solar, it costs me about 20-30 cents in the summer to heat the spa to 101.
If you use the pool a lot (stirring it up), running the pump at a lower speed actually cleans the pool better than running it at high speed. I didn’t believe it until I tried it, but it’s true, and a lot cheaper.
Also, replace those incandescent bulbs in the pool and spa with LEDs(in ours, they were each 300 watts). I put a cheap Chinese one in the spa and a good one from Home Depot in the pool and they both work well. The Chinese one isn’t as bright as the good one from the Depot, but has changing colors and such. The combined power in now only 45 watts.