Based on outside air temp, when is it NOT worth running my pool heater?

I live in Florida, and most of the year it is in the 80's or above, and my heat pump heats my pool just fine at about 1 degree Per Hour. However, in the winter, when the outside temperature is only in the 70's during the day, and can get down to 50's at night, my heat pump becomes VERY inefficient and will only heat the pool at like 1 degree every 2-3 hours.

All the specs for my pool and heat pump are below. What I have been unable to find is a formula to predict at what outside temperature it makes no sense to run the heater.

I like to keep the pool maintained at 85 degrees, but some days the heater runs all day (costs me about $5.50/day) and will not bring it up to temp.

I have an AquaCal H155. The specs and charts for which can be found here: http://www.aquacal.com/heat-pump-information/heaters/heatwave/

It's 132,000 btu. My pool is 15,000 gallons, with a surface area of around 450 sq.ft. Mean depth is 4.5 feet. Thank you!

You may want to invest in a solar cover for your the winter. It will help to insulate the pool so not as much heat escapes. I have a pool and so do many of my neighbors and one of the neighbors mentioned that he keeps a solar cover on it when ever the pool is not being used and it makes a big difference in the pool heating bills.

For More Information on Aquacal Heatwave Follow The Links Below-

Aquacal Heatwave Article

Below Are A Few More Aquacal Heatwave Items:

I hope that the information and also website
links we have presented for Aquacal Heatwave has been a beneficial help. If not, dont hesitate to browse deeper
through our webpage to locate a great deal more concerning Aquacal Heatwave

Search For More Aquacal Heatwave

by using the search box or links on the side of the page. All The Best