Do You Vacuum a Pool on Backwash or Waste: The Ultimate Guide

Every swimming pool requires to be vacuumed to maintain cleanliness and safety. If you have an automatic pool cleaner, it will be a time-saver, but you will also need a manual pool vacuum cleaner because there are things that the automatic machine cannot clean.

However, you might be wondering whether you should vacuum your pool on backwash or waste. These pool cleaning methods are essential, and they can be used interchangeably or sequentially.

Do You Vacuum A Pool On Backwash Or Waste

The lingering question remains, do you vacuum a pool on backwash or waste? Both of the methods are effective, but the circumstances in which they are used are different. This article provides you with the ultimate guide on how and when to vacuum a pool on backwash or waste.

In this post we will cover:

  1. Do You Vacuum a Pool on Backwash or Waste?
  2. How and when do you backwash a sand filter?
  3. How do you vacuum to waste with a cartridge filter?
  4. How do you backwash a cartridge filter system?
  5. How do you clean a pool that has been sitting?

Do You Vacuum a Pool on Backwash or Waste?

Vacuuming a Pool on Backwash

The backwash method is one of the most active settings on a pool filter. Backwashing sanitizes the sand in your pool’s filtration system after vacuuming your pool almost immediately. The backwash setting is used to reverse the flow in the filter and send water out of the waste line.

When using the backwash setting, ensure that the valves are open and that your backwash hose is rolled out. Backwashing is done when the filter pressure in your pool rises to 8–10 psi over the clean starting pressure. That is approximately 20–24 psi depending on the system that you have.

Below is a step-by-step procedure on how to backwash and vacuum a pool on backwash:

How to backwash

Step 1: Turn off your pool’s pump and then rotate the multiport valve to backwash. Avoid turning the filter valve when the pump is running.

Step 2: Turn on the pump so that the dirty water in the pool can flow out through the waste line. Then turn off the pump once the water runs clear in the sight glass of the valve.

Step 3: Rotate the valve to rinse, and then turn on the pump for about 10 to 20 seconds to clean out the filter head.

Step 4: Switch off the pump and rotate the valve to the filter position. Allow the sand in the filter to settle for one minute while you clean out the pump basket.

Step 5. Turn the pump on and continue filtering. Take a reading of the new clean starting pressure to use as a reference for the next backwash.

Step 6: You may need to inspect and possibly change the sand if the pressure of the filter does not reduce after backwashing. You may also need to add water to your pool to replace the backwashed one.

How to vacuum on backwash

Step 1: Begin by inserting the vacuum hose into your pool and positioning the vacuum plate on top of the skimmer but not in the water.

Step 2: To fill the hose with water, place the vacuum head over a return. When water begins to flow out of the skimmer’s end, push the vacuum plate to the top of the skimmer basket.

Step 3: To receive maximum suction close all valves except for the skimmer valve being used.

Step 4: Begin vacuuming and start with the deeper end coming to the shallow one.

Step 6: Check the pressure now and then so that you know when to backwash. Also, empty the skimmer basket when checking the pressure or whenever you vacuum leaves from your pool.

Step 7: When you’re finished vacuuming, open the valves and remove the vacuum.

Vacuuming a Pool on Waste

The waste setting on a pool’s filtration system is responsible for collecting water from the pool and transferring it to the waste channel directly without passing through the filter. The waste setting, in most cases, drains water from a pool partially or completely.

However, it can also be used to vacuum a pool that has a lot of debris and contaminants on the floor of the pool. If you do not have a waste setting on your pool filter, you will not be able to attain maximum hygiene in your pool. That can lead to clogging or blocking of your pool filters.

The waste setting is utilized to minimize the water level of your pool when you want to vacuum your pool to waste. Vacuuming to waste is only possible with filter systems that are controlled by a multi-port valve, which is commonly found on sand filters.

Vacuuming to waste is done when you notice that there is a heavy accumulation of dirt, algae, and other microscopic particles that cannot be caught by the pool’s filter. Vacuuming on waste ejects debris out of the waste hose to prevent it from getting back into the pool.

When you vacuum to waste, you bypass the pool’s filtration system while preventing algae and other debris from passing through the filter and entering the pool again. You will need a vacuum head, a vacuum hose, a telescopic pole, and a skim vac to vacuum to waste.

Here’s a step-by-step guide to vacuuming waste:

Step 1: Start by shutting off the pump and then positioning the multiport flap on top of the waste setting.

Step 2: Switch the pump on and by now, all the water in the pool will flow to the sewer.

Step 3: Shut all the skimmer lines down, leaving only one. Then, reduce the main drain to half its capacity.

Step 4: Reset your pool vacuum to its usual regular vacuuming. That involves connecting the pole and swivel end of your vacuum hose to the vacuum head.

Then slowly lower the head into the water. Completely fill the vacuum hose with water and connect the other head to the skimmer plate.

Step 5: Connect your garden hose pipe after un-wrinkling it to the skimmer to which you connected your vacuum hose pipe and then switch the water on.

Step 6: Then vacuum the swimming pool. If your pool has a deep end, begging vacuuming from there. While vacuuming, keep an eye on the water level because if you allow it to get too low, it will cause your pump to run dry, which can cause serious damage.

Step 7: Close the skimmer and the skimmer flap that you recently vacuumed, and then unleash the main drain flap all the way.

Step 8: Return the multiport valve to the filtration system and switch on the pump. You are now removing water from the pool’s main channel while all of your skimmers are turned off.

Step 9: When the pump has achieved its goal of lowering the main channel valve by 50%, fully open the skimmer flap.


Whether you decide to vacuum your pool on backwash or waste the decision relies on what works best for your pool. However, each cleaning method has some conditions that must be met.

For instance, vacuuming to waste is done when you notice that there is a heavy accumulation of dirt of particles that cannot be caught by the pool’s filter.

The method ejects debris out of the waste hose to prevent it from getting back into the pool. Both method of cleaning the pool are easy and do not require professional help. Just follow the procedures for both methods that we have outline above.


How and when do you backwash a sand filter?

If your sand filter pressure gauge is reading 8–10 lbs above the clean starting pressure, then your sand filter needs backwashing. It is also recommended to backwash your filter after vacuuming to remove impurities and debris that have been vacuumed.

The backwashing process involves turning off a valve to allow water to flow through the filter backward to flush out the dirt therein. In a sand filter, pool water usually flows from top to bottom, but in the backwash process, water flows from bottom to top in reverse.

The reverse water flow flushes out trapped dirt from the sand bed, sending it out through the waste line. A sand filter can have either a multiport valve or a push-pull valve/slide valve.

The multiport valve has six positions, while the slide valve has two positions. You can backwash or filter it with a plunger to change positions. You can either push down or pull up the plunger.

Before turning the filter valve, always make sure that the filter pump is shut off because it can damage the internal parts of the filter or the gasket.

How do you vacuum to waste with a cartridge filter?

Vacuuming to waste entails the pool pump pushing water to the filter, diverting it straight to the waste line while bypassing the cartridges and sand filters.

Cartridge filters do not have valves because they are usually not backwashed. Instead, they are removed and sprayed off with a garden hose.

When it comes to vacuuming to waste with a cartridge filter, there are two options. The first is removing the filter lid and the cartridge and then securely replacing the lid and fully tightening the clamp.

Remove the drain plug and clamp on a 1.5′′ hose adapter and backwash hose using a clamp. Backwash the hose into a storm drain or a location that will not erode or oversaturate.

The second option involves installing a third-way valve in the pipe between the filter and the pump. Some PVC glue, primer, and a bit of pipe are the only extra materials you will need. With a hacksaw, cut out about five inches of the PVC pipe between the filter and pump.

Allow 2-3 inches of clear pipe on both sides for connecting the new valve. Reset the valve lid to allow water to flow straight through the valve for normal filtration, or make a hard 90° turn and exit through port 3.

Clamp a length of backwash hose to a short piece of pipe that has been glued to the valve. Then turn the valve whenever you want to vacuum the waste from a cartridge pool filter or whenever the water level is too high due to excessive rain.

How do you backwash a cartridge filter system?

A cartridge filter cannot be backwashed by reversing the water flow in the filter system of your pool because such filters are not built for reverse water flow. When a cartridge filter is dirty, it should be cleaned by hand or with a garden hose.

Below is the procedure for backwashing a cartridge filter system:

Step 1: Turn off the filter’s power and close the valve that leads to the pool’s outlet. Then, at that point, close the valve connecting the skimmer to the pump inlet.

If you lack valves at these connections, insert a plugin to the skimmer to prevent water from flowing into the pump and another at the pool inlet to prevent water from flowing back into the filter housing.

Step 2: Loosen the air valve on top of the filter, allowing air to enter the cartridge filter housing as pressure is slowly released.

Step 3: Open the filter drainage valve to empty trapped water in the filter housing to prevent recontamination of the freshly cleaned filter when it is reinstalled.

Step 4: Remove the top of the cartridge filter to access the cartridge. Lift the filter from the housing and hose it off using a garden hose. Also, hose down the housing of the filter.

Step 5: Prepare a chemical bath in a large container for your filter. Make a solution by combining a cup of trisodium phosphate (TSP) with four cups of water. Repeat the ration until the filter is covered in the solution.

Step 6: Leave the cartridge to soak overnight in the solution before rinsing it off with a garden hose. Replace the filter and place the top back on its housing.

Step 7: Close the drainage valve, then open the inlet valves to the filter and pump. Unplug the skimmer and pool return inlets if you plugged them in earlier.

Step 8: Switch on the filter and open the air relief valve on the unit’s top. Close the air valve when the water starts spraying out. At this point, the cartridge filter is ready to clean the pool again.

How do you clean a pool that has been sitting?

A pool that has been sitting has a lot of dirt, debris, and muck to clean. If you consider draining as an option, it will depend on the type of pool that you have.

However, if you have a vinyl or fiberglass pool, avoid draining because fiberglass is lightweight, and old vinyl liners can shrink. Water removal can affect the longevity and quality of their material.

When draining is an option available to you, use a trash pump to clean the debris in your pool. The trash pump can clean your pool in an hour because it can soak up leaves, twigs, and solids the size of a golf ball.

You can clean your pool using a smaller gas pump if the condition is not that bad. To avoid floating your pool, do not drain it immediately after heavy rain. Once you are done draining, fill the pool immediately.

After draining it is recommended to acid wash or pressure wash the pool for a better result. Use a mild soap and low pressure when cleaning a pool with vinyl or one with fiberglass material.

When draining is not an option available to you, use leaf nets and a leaf bagger to remove 99 percent of organic debris from your pool. Repeat this until the net comes back clean. Then treat the water to balance pH, alkalinity, and stabilizer.

Shock your pool until the water turns a blue-grey color. You must be prepared to use 5-10 lbs per 10,000 gallons of water. You can also run the filter until your pool water is completely purified.

Use flocculant to make dust particles settle on the pool’s bottom. A clarifier can also be used to settle suspended particles. Fill your pool with water, then use your vacuum to help lighten the stains by setting the multi-port filter valve.

Do You Vacuum A Pool On Backwash Or Waste