They can use salt or chlorine but most people choose salt
it keeps the pool clean
to keep it clean. ..
You put chlorine in pools, to kill bugs and to stop mosquitoes from laying eggs in the water.
chlorine
Pools use chlorine to keep the water clean.
Chlorine.
like in pools, it keeps em clean ;]
to keep the water clean and kill germs
Chlorine is the most used (to disinfect and keep clean), but Bromine is also used.
beacause chlorine is a chemical used to clean water
It is most commonly used in keeping pools clean.
Clean water Kills Bacteria in swimming pools