How Long Should I Run My Pump to Clear Cloudy Water?

Run it continuously. Twenty-four hours a day, until the water is clear. Cloudy water is a mechanical problem as much as a chemical one, and the only thing that physically removes suspended particles is water passing through the filter. Most pools clear within 24 to 72 hours of nonstop running with a clean filter.

Why turnover is the number that matters

Turnover is the time it takes to circulate a volume of water equal to your entire pool through the filter once. Normal maintenance calls for one turnover per day. Clearing a cloudy pool calls for two.

To find yours:

• Pool volume in gallons divided by pump flow rate in gallons per minute equals turnover time in minutes
• Divide by 60 for hours

A 15,000 gallon pool with a pump moving 50 gallons per minute turns over in 300 minutes, or five hours. One turnover a day means five hours of run time. Two turnovers means ten. Running 24 hours gives you almost five turnovers, which is what actually clears haze quickly.

Note that a single turnover does not filter 100 percent of the water. Filtered and unfiltered water mix continuously, so one turnover realistically processes around 60 to 65 percent of the volume. That is another reason clearing a pool needs multiples.

Speed settings on a variable speed pump

Variable speed pumps save money by running slowly for long hours. That is the right setting for maintenance and the wrong one for clearing a cloudy pool.

While clearing, run at a mid to high speed. You want the flow rate high enough that water is actively moving throughout the pool, including the deep end corners where fine particles settle. Once the water is clear, go back to your efficiency schedule.

One caution: a very high flow rate through a sand filter can push fine particles straight through the media rather than trapping them. If your filter is sized close to your pump, a moderate speed will filter better than full throttle.

Watch filter pressure while you do this

Long run times load a filter fast. Check the pressure gauge at least twice a day during a clear-up.

When the gauge reads 8 to 10 psi above the clean starting pressure, flow has dropped enough that you are no longer filtering effectively. Backwash a sand or DE filter, or pull and rinse cartridges, then resume.

On a badly clouded pool it is normal to clean the filter two or three times in 48 hours. That is the filter doing its job, not failing.

Write your clean pressure on the filter housing. Without that baseline the gauge number tells you nothing.

Circulation habits that shorten the timeline

• Brush walls, steps and floor once a day so settled particles rejoin the water column
• Angle return jets slightly downward and in one direction to create a rotating flow rather than a dead center
• Empty the pump and skimmer baskets daily, since a half-full basket quietly cuts your flow rate
• Keep the water level at the middle of the skimmer opening so it never draws air

Run times in the Florida Keys

Island pools generally need more hours than the mainland rule of thumb suggests. UV here is intense nearly year round, chlorine demand stays high, and the water stays warm enough that biological activity never really pauses, so there is no low-demand winter schedule the way there is up the peninsula. Summer brings the other pressure: heavy afternoon rain washes in organic debris and dilutes chemistry in the same hour, and salt air keeps a steady load of fine particulate on the surface. During rental season with heavy bather loads, eight to twelve hours a day is a realistic baseline here, and pushing to continuous running during a clear-up is not unusual at all.

When more run time is not the answer

If the pool has run continuously for 72 hours with balanced chemistry and a clean filter and it is still hazy, stop and look at the equipment. Worn sand media, torn DE grids, split cartridges, a bad multiport spider gasket or an air leak on the suction side will all keep water cloudy no matter how many hours you add.

The practical takeaway: leave the pump running until the water is clear, and let filter pressure, not the clock, tell you when to service the filter.