Solar heating is very simple for residential swimming pools. The pool water that normally passes through the pool filter is simply diverted to pass through solar collectors before it returns to the pool.

The solar collectors, being black, absorb the energy of the sun and transfer it to the pool water that is passing through them - heating the water. The existing pool filter pump is all that is necessary
, 99% of the time, to circulate the water through the solar collectors and return it to the pool. A valve - either manually or electronically operated - is used to divert the water to or away from the solar collectors. 

The Flash movies below illustrate the pool water removing the heat energy from a bank of 6 solar collectors and how the water is drawn from the pool, passed through the pool filter and through the solar control valve. When the solar system is off the water returns directly to the pool. When the solar system is on, the water travels into the solar collectors before return to the pool (warmer!).


Note how the pool water flows into the bottom of the solar collectors and out the top - not the other way around!

 

This movie shows how pool water flows through your pump & filter and solar control valve.

Next: Sizing Your Solar Pool Heating System