Cloudy Water
So the pool isn't sparkling the way it normally does. Not only is it less appealing, it's also very dangerous to keep a cloudy pool.
NOTICE
Before doing any repairs or troubleshooting, make sure that no one is swimming and close the pool.
Look for the main drain at the bottom of the pool. If you cannot see the main drain through the water, the pool must remain closed until the water clears up.
Check if the Filter Pump is running
Pool water needs to circulate through a filter to stay clear. The Filter Pump is what keeps the water flowing through the filter and back into pool, crystal clear. If the Filter Pump stops functioning, the pool can get very cloudy, very quickly.
Go into the pool pump room or pool equipment area and make sure that the Filter Pump Motor is running. If the motor is not running, it may have triggered a circuit breaker or the motor has gone out and needs to be replaced.
Backwash the Filter
Backwashing a filter flushes out all of the caught particles from the filter media. Filters can get clogged in a matter of just a few days if a pool has had a lot of activity. Sand filters for commercial pools must be backwashed often, at least once per week or even once per day depending on how much the pools are used.
D.E. (diatomaceous earth) filters for commercial pools should be backwashed and recharged with new D.E. powder at least once every two weeks or once a week depending on how much the pools are used.
Most pool filters will have a pressure gauge installed on the top lid that allows you to see how much pressure in pounds per square inch (psi) is inside the filter. A clean filter will usually operate between 10 - 20 psi. When the pressure reaches around 30 psi, it usually means it's time to backwash the filter.
For sand filters, if the pool remains cloudy even after backwashing, there may be a problem with the sand inside of the filter not properly filtering the water. Refer to our article about pool filters and check the section about "bad sand".
Check the Baskets
Pool systems utilize baskets in several areas to catch large debris. These baskets prevent Filter Pumps and any other pool pumps from getting jammed with any leaves or trash that inevitably falls into the pool.
Check the basket inside of the Filter Pump. If the basket is full, it may be preventing the water from flowing sufficiently. Clear out all of the caught material from the basket and place it back in the pump.
Be sure to check all of the skimmer baskets around the edges of the pool and make sure they are all empty.
Cyanuric Acid
High cyanuric acid can cause pool water to be cloudy. Refer to our article on Cyanuric Acid and how you can lower it.