I've read a bunch of the other threads on heaters. I have a specific question.
I'm in Montana, and am installing a 15x30 AGP in the ground (deck surround). I currently have 8 2x20 solar panels that I'll be using, roughly 90% of the surface area.
Our sun intensity when it's out is quite high because we're at 4500ft. But, overnight temps can dip below 50, even in the summer time. It's supposed to hit 37 on Sunday night.
I use a solar cover, and I'm wrapping the pool in bubble insulation for additional heat retention, so my heat retention is good.
I'm considering either a propane (our source) heater for supplemental heating, or a heat pump, and I need to decide soon so that I can wire/plumb appropriately.
I know that the gas-based heating systems can be very expensive to run (we pay about 2.50/gallon during the summer), and the heat pumps can take a long time to work, plus they are expensive.
We'll have a hot tub as well, so I'm wondering if we just decide that the pool heating is not worth it, swim in the pool when it's hot, stick to the hot tub when it's not as warm, and add a couple of solar panels for good measure.
Anyone have any thoughts on this? By the time I spend the money on the pool heater and paying to run it, I could buy a 2nd hot tub. ;->