Solar Sun RingsPortable Above Ground Inground Swimming Pool Hot Tub Spa Heating Accessory Circular Heater Solar Cover, Blue (6 Pack)

Just ordered 6 more. Then I'll have 1-2 extra so when my terriers puncture it, I'll have a backup.I'll write back with info on "heating" capability once I have more of the pool covered (75%-80%).Reason for Purchase:We purchased to keep evaporation down and to keep heat in at night. In Napa, it dips down into 50s/60s all summer. Also, the very small possibility they will help extend our swim season. We just installed a new energy efficient gas pump heater to save on our crazy gas bills and water usage.PROs:(Partial list until further observations)1. Magnets hold them together and make it easier to retrieve2. Has handles for easy hanging (small)3.CONs:1. Price points are high for essentially a piece of floating plastic. $30-32/each ($300 for our pool)2. Instructions have pictures but there should be more clarity on "over-filling".Examples:Fill "halfway" and see if they will float. Or... They WILL appear grossly under inflated...so test before continuing to fill.3. Not a CON as much as a caution:Unfold all of them and lay flat as the instructions say (I stacked mine).4. Take the time to work out the crimped edges, especially the magnet pockets and the folded handles. WAIT for them to soften (sun helped).NOTE: This step will allow the air to distribute more evenly and easily .... You Will NOT regret this step because it takes SO little air that you'll NEED the air to be able to move very easily while inflating.4. It is NOT reasonable to instruct people to manually blow to inflated. I could NOT do this...got dizzy too fast and I have 12 to fill!!!Logical Solution:a. Follow what I said in #3;b. BE CAREFUL AND METHODICAL and use a pump.IMPORTANT: First Determine the number of seconds needed and use that number for all the rings.NOTE:I counted to 10 (one one thousand, two one thousand, etc.);c. Depending on your pump, you might need to count only to 5 or so.d. Determine your count by looking at the ring and if it looks like it is ONLY a quarter full, STOP!!e. They will look pitifully under inflated.f. PROOF: I filled one for 12 seconds and it looked under inflated; HOWEVER, it curled!!!! I pushed some air out and it is still curled a little. See my pictures.That's it folks... no sinkers, leakers or fly aways .. all good.More later....

Still too soon to tell if they work or not as we are still in the 90s here. But one thing for sure, they definitely reduce the effectiveness of the skimmer and make maintaining a clean pool overall more difficult. When we determine if they helped to hold temperature stars may go up. Jury ia still out on that.UPDATE*** one sprung a leak within a day. Seller replaced it straightaway so good on them. Within about 6 weeks a second sprung a leak. They can be patched and the supplied patches DO work. Above I mentioned that they complicate cleaning. This is for sure. They very much reduce the effectiveness of the skimmer and overall make maintenance more difficult. Now the big question: Do they work? Sadly I don’t believe so. Despite putting them in in late August when we are still in the low to mid 90s air temps & the pool as in the middle 80’s, as soon as the shorter day and cooler weather crept around in early October, the pool did drop to the mid 70s. It DID hold there for a while. But the first cool nights we got, the pool dropped to the mid and then low 60s with just two cool nights (temps in the 50s).Perhaps they got us an extra week or two of swimming. Perhaps not. The water became too cool to swim comfortably this year with these devices as last year without. As the leaves are beginning to fall here in earnest from our trees that DO drop leaves in South Louisiana (which is no all of them) our pool technician informed us that they will HAVE to come out in order to maintain the pool. I agree. They just get too much in the way during the leaf drop season.What did they do? I do believe they helped significantly with evaporation. That normally isnt an issue here as out tropical to sub tropical climate gives us 70-80 inches of rain a year, but this year we are in an extremely unusual (for us) drought so I do know that the slowed evaporation and kept us from having to refill as often.Ultimately I really WANTED these to work. The “common sense” and skeptical side of my brain said they wouldn’t. The scientific side said they might, and of course the reviews here (many of them) said the definitely did. Perhaps an extra week of swimming? Question is, is that worth almost $400-500 and the maintenance headaches they caused? We have them in storage now and plan to re deploy them in the spring hoping that hey may warm the pool a few weeks earlier! Since we have them, why not try. But I dont think I would buy them again or replace them when they wear out.

These work well, enough to slow down the pool cooling down at night during the winter and whenever there is sunlight, will boost the temperature by about 10 degrees. However, 6 of the 18 I purchased came with small pinhole leaks, 3 which were easily fixed but 3 that occurred at the seams and will not seal using a variety of sealants. Product support is virtually non-existent, with a link to a support website that doesn't exist.