"It aint redneck if it works"

I'm guessing you run it and shut it off, or is it continuesly running while you are using the pool? I'd think it would hold the temp for a long enough period to swing without having it on, after it got to temp.

@RustyRatRod I know the heater for my old hot tub, approximately 900 gallons, took a whole day to heat up to temp (103), and still only hit diy's temp after about 20 hours. I'd think that a water bed heater would never get do a thing you'd notice on a pool this size.