How do I backwash my pool filter?

Author: scraper  |  Last update: Thursday, July 16, 2026

Backwashing a pool filter cleans the trapped debris out of a sand or DE (Diatomaceous Earth) filter. You should do this when your pool's pressure gauge reads 8 to 10 PSI higher than its normal clean operating pressure, or when water flow from the return jets is noticeably weak.

Do you run the pump when you backwash?

Turn off your pool's pump and filtration system. Set the filter value to BACKWASH and ensure the handle locks in place. Turn the pump on and you'll see water flow through the view glass. Wait until the filter view glass is clear.

When you backwash a pool, where does the water come from?

When you backwash a pool, the water comes directly from the pool itself. The pool pump pulls water from the skimmer and main drain, forces it in reverse through the filter to dislodge trapped debris, and expels it out of the waste line.

What comes first, backwash or rinse?

Always backwash first, then rinse.

What is the proper way to backwash a pool?

Backwashing a pool cleans the filter by reversing water flow to flush trapped dirt and debris out through a waste line. It is necessary when your pressure gauge reads 8-10 PSI above normal or when pool jets feel weak. Always shut off your pool pump before changing valve settings to prevent damage.

How To BACKWASH A POOL FILTER (The Right Way)

Will shocking a pool get rid of dirt?

Pool shock is a chemical treatment that helps break down contaminants – such as leaves, dirt and debris, even oils from your skin -- that can gradually build up in your pool water. Shocking your pool as part of your weekly pool maintenance routine will help keep your water clear and balanced.

What happens if I don't rinse after backwash?

If you don't rinse after backwashing, residual dirt and loose debris trapped in your filter system will be pumped directly back into your pool. This creates a cloudy "puff" of dirty water that exits through your return jets, undoing the cleaning you just performed.

How much water comes out when you backwash a pool?

You lose approximately 200 to 500 gallons (750 to 1,900 liters) of water per backwash cycle. The exact amount depends on the size of your pool filter, the horsepower of your pump, and how long you run the system to clear out the debris.

How long does backwashing take?

Backwash your pool filter for 2 to 3 minutes, or until the water runs completely clear through the sight glass. Always follow up with a 30 to 60-second Rinse cycle to resettle the sand and flush out any remaining debris.

How do you know when backwash is done?

Backwashing a sand or DE filter is a simple task. Shut off the pump, set the multiport valve or slide valve handle to the backwash position, roll out the backwash hose and turn the pump on again. Backwash for 3-4 minutes or until the water runs clear, then shut the pump off and return the valve to the filter position.

How much water should a pool lose in 3 days?

Generally speaking, pools lose approximately 1/4” of water per day on average, though this can vary due to factors like wind, temperature, humidity and of course, the pool's total surface area.

What happens if you backwash too long?

Backwashing too long alone isnt harmful...running out of water running dry, stuff like that is. Sound like just needs to be fully primed. it will seem to suck air if not primed and air relief is open. Fill the basket with water then close the pump lid, then start the pump.

How many minutes should I backwash my pool?

Backwash your pool filter for 1 to 2 minutes (or until the water runs clear). Always follow this with a 30-second rinse to settle the filter media. Do not over-backwash, as filters actually trap dirt more efficiently when slightly dirty.

What will ruin a pool pump?

Pool pumps typically last 8 to 12 years, but premature failure usually stems from overheating, water leaks, or debris blockages. Common culprits include a failing motor (often due to worn bearings), electrical shorts, dry running caused by air leaks, and impeller damage from clogged debris.

Why is my pool losing 2 inches of water a day?

All pools lose some water daily due to evaporation. Under normal conditions, expect about 1/4 inch per day, with weekly losses typically ranging up to 2 inches at most. However, factors like high temperatures, low humidity, wind, and pool activity can increase evaporation, leading to greater water loss.

At what pressure do I backwash my pool?

Backwash your pool filter when the pressure gauge reads 8 to 10 PSI higher than your established "clean" baseline. Continuing to run the system past this point decreases water circulation and filtration efficiency.

Where does the water come from when you backwash a pool?

When you backwash a pool, the water comes directly from the pool itself. The pool pump pulls water from the skimmer and main drain, forces it in reverse through the filter to dislodge trapped debris, and expels it out of the waste line.

Do I need to run backwash and rinse cycle equal time?

Run the backwash until the water in the sight glass (or the water you can see exiting) runs clear. Rinse Cycle: After backwashing, switch the filter to the rinse setting. Run it for 1-2 minutes to clear out any remaining debris and prevent dirt from re-entering the pool.

Why does the bottom of my pool get dirty in 2 days after vacuuming?

With time the sand in your filtration system will break down into smaller particles and get out into the pool. These small particles will have no problem going through the filtration system and in the end, get mixed with dirt. This could be a reason your pool gets dirty even after you have vacuumed it.

Which is first, backwash or rinse?

Always backwash first, then rinse.

Why do I have to backwash my pool every day?

Backwashing your pool every day usually indicates that your filter is dealing with an excessive amount of contaminants, such as active algae growth, heavy pollen, or fine debris. A daily need to backwash, especially when pressure rises quickly, suggests the filter is working overtime to clear a "dirty" pool, rather than just routine maintenance.

Why do people put baking soda in their swimming pools?

Baking soda (sodium bicarbonate) acts as a natural buffer that raises both your pool's total alkalinity and its pH. It prevents severe pH fluctuations (known as "pH bounce"), clears cloudy water, prevents equipment corrosion, and helps your chlorine sanitize more effectively.

What is a cowboy pool?

A cowboy pool (also known as a stock tank pool) is a large, galvanized steel livestock tank that has been repurposed into an above-ground swimming pool or soaking tub. They serve as a popular, budget-friendly alternative to traditional in-ground pools.

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