I know it seems silly to have to have a pool heater in Louisiana, but our ABG pool seems to be stuck at about 76-78 degrees, which is just a little too chilly for comfort. I'm sure when day time temps get into mid- to high-90's, water temp won't be a problem. Until then, we decided to try to heat the water.
After reading all of the threads about solar tube water heaters, looking at a few other sites, and all of the solar water heater images on Google, it was apparent that basically all we needed was to pump water through a hose on the roof and back into the pool. I had a spare water pump from my saltwater aquarium (may or may not hold up to pool chemicals), so all we needed was tubing.
It looked like the method used by others of winding the tubing onto wood, metal, or PVC brackets was a pain in the butt, especially when it comes to securing the tubing with zip ties, wire ties, etc. I wanted to avoid this part altogether.
Also, it seems to me that by coiling the tubing right next to each other, some sun light contact is lost that could be gained by leaving small gaps between the tubes so some side-heating of the tube can occur. Maybe my thinking on this is wrong, but it makes sense to me for now...
So, I decided to just lay some tubing on our porch roof (300ft, minus the runs to/from the pool), and secured each end of the tube onto 2x4's. This allows the tubing to get more sun contact by not being secured side-by-side, prevented the problem (pain) of coiling the tube onto a mount, and therefore only took about 30 minutes to install!
A note on the pump: So the pump I have is 700gph. Initially I thought that the head pressure would slow this pump down a lot, but then I realized that since the water is going up and right back down to the pool, without any air breaks in between, head pressure isn't an issue. However, the friction loss in the tubing and fittings does slow down the flow far from the 700gph.
The water going from the pool right now is 76, and coming back from the roof is about 80. Not a huge increase, but hopefully over a day or two, it will bring the pool up enough to take a swim.
A quick question: Do you guys think the tubing on the roof would heat more efficiently on the shingled roof rather than the metal roof? The metal gets super hot, but when clouds pass over, it quickly cools, and so does the tube and water. The shingle roof however seems to store the heat, and stays warm for a while under clouds. Also, should I add another 200-300ft on the roof to heat the water even more? It has been running for 3hrs this morning with no pool temp increase yet. Thoughts?