DIY Black-Pipe Solar Heaters

Turn off your swimming pool's pump by flipping its power switch or unplugging it from the power outlet to which it is attached.

Close the intake and output water vents inside the swimming pool; some have built-in flaps that you can flip shut, while others have a detachable plug that you must screw in place.

Disconnect the hose connected to the water output valve on the swimming pool and the water pump using a Phillips-head screwdriver. Turn the screw on the metal hose clamp that is holding the hose in place, then slide the pipe from the pump. Set the hose aside.

Purchase two threaded PVC adapters, which are plastic tubes with threads on one end. The exact size you require depends on your garden hose and water pump. Purchase one adapter that is large enough to screw onto your water pump's output valve, and one that is large enough to slide into the end of the garden hose.

Screw a PVC adapter into the water output valve on the water pump, then slide one end of the garden hose onto the opposite end of the adapter. Wrap a metal hose clamp around the garden hose, then tighten its screw to secure the clamp to the adapter.

Connect the second adapter to your swimming pool's output valve where the hose was connected. Slide the free end of the garden hose onto the adapter on the swimming pool, then fix it in place with a metal hose clamp.

Open the water vents inside the swimming pool. Verify that the black hose is not kinked or twisted, then turn on the pump. The water will take a minute or two to circulate through the black hose, then will exit into the swimming pool. When the hose is in direct sunlight, the black plastic will be heated, which will in turn warm the water, which is then pumped into the swimming pool.