I'm tired of my pool cooling down too much, and I hated messing with the solar blanket while it lasted. I thought about sun rings. Someone a year or two ago made some at home using hulahoops and polyethylene.
I thought about it and remembered that I have plenty of polyethylene drip irrigation tube leftover from an unsuccessful experiment at a homemade solar heater, and half a roll of leftover black trash bags from the last homeowner, so I'm experimenting.
Step one: make a loop of tubing connecting the ends with a drip emitter. It floats just fine.
Step two: slit a trash bag and fuse the bag to it, sort of tack welding it with a soldering iron. Still floats, even with water splashed on it. Caves in with strong current inside the hot tub.
Step three: make another loop using a piece of dowel as the splice. Use hot melt glue to stick it all together.
Step four, durability testing as shown in photo.
Thus far, zero expense. Everything was junk I already owned. Contemplating larger diameter tubing for better rigidity and thicker plastic. These trash bags are .75mil. Sheet polyethylene is 4 or 6 mil, should be more durable. More updates to come.