If algae becomes a problem.
Get the water tested, ph and alkaline levels will affect the effectiveness of the chlorine in the water.
If using salt system, water temperature needs to be higher than 65 F for the system to work.
When the water is too cold use powdered chlorine to shock the pool and algaecide to slow down algae growth.
Best way to clean the pool rapidly is vacuum all the algae, backwash or clean the cartridges than shock the pool.
Repeat this process every day until the pool clears up.