Most efficient way to heat pool with gas heater?

[Vital Signs]

Just bought a house with pool and it has a raypack gas heater (I need to get the model number) and I was wondering what's the most efficient way to use it. I mean I like the idea of warm water enough to use a heater but I'd also like to save money if I can use it in a certain way.

Should I leave it at a set temp or only turn it on when I anticipate using the pool? How quickly do these things usually work? Can I expect same day heating up to temp or do I need a days planning to have a warm pool? I've got a decent amount of water.

Also I've got an auto cover, do these usually help retain heat or is it better to keep it open when the sun is out to get some solar help.

 

[ajw22]

How many BTUs in your heater? Probably a 400K BTU heater.

A 400K heater will heat your 39K pool by 1 degree hour or less. How quickly your pool will warm depends on how many degrees of temperature rise you want.

A cover prevents heat loos from evaporation when the air temperature is less then the water temperature.

You will not get a lot of solar heat from opening the cover. However a pool needs to breath and you should open your cover for some periods of time.

 

[Vital Signs]

Looks like my Raypack heater model is a 406 so it is indeed a 400k btu unit. After doing a bit more research I think I'll just use turn it on when needed as opposed to keeping it running to maintain a certain temp