well..last night, here's how things worked out. i'm quite happy and thrilled with myself that i invested in a pool cover.

heated my pool up from a 63 F startup temp to 82. (it took 27 hours so i think that's about a 2/3 degree average rise per hour. i let the heater and pump that point go into my desired 6 hour cycle with the temp on heater being left at 82. the pump/heater were on until 2am with the heater cycling on and off as necessary to maintain 82.

at 7:30am this morning, i manually started the system (you can't see temp on heater until the heater is powered on). i was initially shocked to see the temp at 63 and thought..ouch...i'm back to square one..seconds later, it jumps to 76..i'm thinking..6 degree heat loss from 2am to 7:30am..average overnight temperature was about 55..6 to 8am this morning it actually dropped to about 42! within one minute of circulation it popped up to 80...i thought ok..now, we're talking! 2 degree overnight loss was awesome..within 1/2 hour it was up to 81...

so, what this tells me is that my heater while not bringing the temp up in fall by 1 degree per hour as intended, is very easily able to "maintain" the temp once up to optimum temp.

it also tells me that a solar cover provides a huge benefit..i don't know what the temp drop would have been without it but i have to guess at least 8 degrees versus 2 from what i read.

the best investment in my "redone system" for cost efficiency will no doubt have been the solar cover.

i'm now into the cycle and until we decide to close will check the temp each morning and use that as a guage..the key for me will be how much it has to be heated up post the overnight "shutdown" to maintain 82. it would be nice if i can keep it running to end of september. after that point, the daytime airtime is too cold for my kids to have interest. that will also be the key..if it's in the teens post 20+, i know my kids won't want to bother.

when i first got the pool, i kept it open until mid-october and it got to the point where i was heating it for 12 hours to maintain temp (old heater, no cover) for 1 hour of swimming 3x per week. just isn't worth it in my mind at that point!