I have been forced by the weather to abandon any hope of getting my pool back to swimmable temp. With highs only reaching at best the mid 70's, and overnight lows dropping into the low 50's, any gains I make with my small heater are taken back every day.
With too many other things needing my attention, I just don't have the time to devote to keeping a god hot fire in the heater. If the time was available, I'm sure I could keep the pool at least in the high 70's low 80's.
As projects get completed, I'll then be able to make improvements to my heater system, and get it plumbed into the main filtering/circulation system now that I have a "real" pool pump.