Wouldn't it be nice if the swimming pool were just a little bit warmer?
Tired or hearing the kids complain about how cold the pool is?
Don't want to spend a lot of time or money on some DIY solar pool heater?
Well, here's the instructable for you...
I just set up my pool and realized that with the chilly water coming out of the faucet it was going to take some time until the pool warmed up to a comfortable temperature. However, the thought came to me that I had 250 feet of black garden hose and a submersible pump laying around and that I might try using 'as is' without building anything just to see if running pool water through the hose in the sunshine would help. IT DID!
For this project you'll need:
- 250 feet of black garden hose (or some amount - you decide)
- A pump (optional if you want to tap the return of your pool filter; I had a 1/6 hp submersible pump)
- Thermometer (optional - only if you want to feel vindicated when others scoff at you dragging hoses around)
Step 1: Pick Your Location
Obviously you want to pick a location for your temporary solar pool heater that will get lots of sunshine and not be in the way. I decided on my roof. This was a good and bad choice. Good because it was out of the way and got lots of sun, and bad because it was on the top of a two story home. Also bad because since it was two stories up there was quite a 'head' on the water to push it up onto the roof. In fact my submersible pump was rated 0 gallons per minute (gpm) at a 20 foot head. So with my pump I had on hand I had no flow! A pool filter pump would probably also be challenged to get water up onto the roof.
I was just starting to fill my pool and so I had the water run out of my spigot and go directly up onto my roof and then drain into the pool to fill it. This worked fine until the pool was full (10,000 gallons later).
Step 2: Layout Your Garden Hose
Be careful on the roof. In fact it is advisable to use a safety harness and rope tied off to the structure.
I looped the hose back and forth on the sunny side of my roof. I also looped about a three foot loop of hose over the peak of the roof to 'anchor' the coils so that the weight of the hose did not cause the hose to slide off the roof. This is also the reason I ran the loops vertically, so that the hose would not roll horizontally off the roof. After I put it all into place I had a 6 degree F increase in water temperature! (74F -> 80F). Yeah!!!
Step 3: Pick a New Location for the Garden Hose
Well, I knew I could only use my roof location until the pool was full since I had to use the municipal water system's pressure to get the water up onto the roof. I had placed the hose on the roof while it full of water and this worked fine until I turned the tap off and the water all drained into the pool. When the tap was turned back on the next day the weight of the length of hose up onto the roof full of water was greater than my now empty counterbalance loops and nearly the entire amount of hose slid off the roof and into a heap on the ground.
So my second attempt at a good location was on the backyard lawn. This was not a bad location although I have to move the hose to mow the lawn. It certainly was much easier and safer to lay out the loops on the grass than on the roof. The lawn location also allowed me to use my 1/6hp submersible pump since there was only the raise of the 5 feet to get back into the pool.
Step 4: Hook It All Up and Start Heating
Layout the garden hose again. This time on the lawn.
Hook up the submersible pump, submerse it and fire it up!
With the 250' of hose laid out on the lawn I had a 2 gallon per minute flow (2 gpm) and the water temperature raise of seven degrees F. (78 ->85F)
Go enjoy your warm pool!