Pool Solar Heaters, Covers, and Blankets
In our northern climate, summers can be fairly cool at times. And wouldn't you know it? The first year we have a pool we have a summer that is nearly the coldest on record! But even so, our 15 ft above ground Intex metal frame pool is "swimmable" at temperatures of about 75 or higher. To help things along on days with cooler temperatures, we bought a clear solar pool blanket desiged to capture additional heat from the sun. I chose the clear cover as it will allow more sunlight in, and was recommended to me over a blue color. After searching around a bit, I found clear pool covers (like the one I bought) to run about $60-$90 ( shipping included). We got an 8-mil cover at poolcenter.com but the newest one is now 16 mil and offers an 8-year warranty - the thicker the cover, the easier to handle and roll up. A photo of the cover we bought is shown below. These pool covers look almost like shipping bubble wrap, but they are more heavy duty (See http://www.ehow.com/how-does_4699727_bubble-wrap-heat-pool.html ). Also, it would cost a lot to make a homemade solar pool heater - I checked!
Besides the poolcenter cover, I found similar covers at ebay. Also, there is a less expenive solar cover available at Intex, but it is thinner in guage. The thicker the cover, the longer it will last, and the easier it is to roll up. Make sure to get a clear solar blanket.
UPDATE: We had this clear solar blanket on during a sunny but fairly cool and windy day where the temp only topped out at barely 70 degrees. At about 5:30PM we took the cover off and took a swim (68 degrees out) and the water was nice -This solar heater cover works! Ironically, on cool clear dry days, the solar blanket heater works even better than on warmer days that are less clear - on dry days the sun can really heat things up. On another day it was down to 48 the night before and only got into the high 60's during the day (but it was clear and sunny), and by 5:30PM the water was nice!
Note: You should put the cover on with the bubbles down. The easiest way to put the cover on and take it off is to roll it up in a long tube and then unroll it onto the pool - when off the pool, leave in a rolled up state out of the way.
Final Note: Do not go with a blue solar blanket - the blue does not allow as much light through and will not work nearly as well as a clear solar blanekt to capture the heat - I got a blue one by mistake and was very disappointed! !