Simplify the following text for a Grade 8 native English-speaking person.
Original: The most common pool styles are play pool , freeform pool , geometric pool , lap pool , diving pool , infinity pool , spool , and the perimeter overflow pool .
Simplified: Swimming pool heating costs can be significantly reduced by using a pool cover . Use of a pool cover also can help reduce the amount of chemicals ( chlorine , etc ) required by the pool .