I have a large pool (80,000 gal) which is in a rental property, as a result the heaters (3 of them!) are off most of the time.
When we have a booking, say once a month, we fire up the heaters and it can take 3-4 days to get up to 85-88!!
If the air temp is low, or it rains we do not even achieve that!
Question: Could I add a LP heater to the row of heat pumps (should it go first or last??) to give that initial boost for heat then allow the HP to keep it there??
Perhaps let the gas heater kick in occasionally when needed??