Winter propane heating

[Guest]

We're looking at installing a lap pool - mid-Missouri. I'm having trouble finding estimates on propane usage if we heat it during the winter, or at least the milder parts of the winter when the temps are 20-40 degrees. It's a large inground pool (24x50) but we are putting on a automatic solar cover that will keep it covered when we are not using it.

Someone local that we know with a similar but smaller pool has a heat pump that lets them swim from April to October. We swim for exercise daily and would like to trade in a health club membership cost for pool heating costs (plus gas cost of driving to said health club).

At 400,000 BTUs, I can do the math on the propane usage, but I have no idea how long the heater would be running to maintain temps in the winter with the solar cover on.

Any thoughts? Thanks in advance!