text: how can we heat an above ground round pool, 24 feet in diameter, without spending a lot of money? many years ago someone i knew had used a glass door to generate solar heat for a pool but no one knows what i'm talking about.  we have lots of sun but how do we utilize it on the cheap? with plenty of sun--get some black drainage pipe, the corrugated 3" stuff.  stretch it out in the sun so the entrance is higher than where you want it to exit.  i get about 10-15 degrees higher water temperature at 25 feet.  helped us get in the pool a couple weeks earlier and stayed in it for awhile longer.  i found this on the web some time ago, the next step is to build a plastic box and use a coil of the pipe, may increase temp by another several degrees--i haven't figured it was worthwhile yet.