When to Vacuum a Pool to Waste




Purchasing a pool for your home is an exciting time. Owning a pool brings with it some new responsibilities, and you will probably have many questions. One of these will undoubtedly be when to vacuum pool on filter or waste?

You will need to vacuum your pool to waste when there is heavy debris, dirt, or algae in the pool to prevent it clogging up the filter. Using the waste setting on your pool’s pump will bypass the filter system and the dirty water expelled rather than going back into the pool.

Here are some tips on when to vacuum to waste and how to do so correctly.

When to Vacuum a Pool to Waste
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When to Use Waste on Pool Filter?

You will not have to vacuum your pool to waste very often if you keep it maintained and cleaned regularly. Large amounts of debris and algae are not likely to build up in a pool that is skimmed, vacuumed on filter and chemically treated often.

To keep your new pool looking nice, you will need to keep a healthy cleaning routine.

The times I vacuum my pool to waste are generally:

  • When I give the pool its first clean of the season, after it has not been used over the winter.
  • After a big storm that has blown lots of leaves and other debris into the pool that has settled on the bottom. Where I live we get a wind called a Calima which carries lots of dust across the sea from the Sahara Desert and dumps it here. That settles on the bottom of the pool and is so fine that the filter would struggle to trap it.
  • If I have had a heavy algae infestation and the dead algae is now on the bottom of the pool then vacuuming on the filter setting is likely to deposit much of the dead algae back in the pool as not all of it will be trapped by the filter. So ejecting the water out of the pool prevents this. Read: How to remove dead algae from a pool

How do I vacuum my pool to waste?

What Tools Will I Need To Vacuum a Pool to Waste?

What tools will I need to vacuum a pool to waste?

Buying a new pool comes with a lot of extra expenses and equipment. You will want to make sure you have the correct supplies before vacuuming your pool to waste. 

You will need a backwash hose to attach to the pump outlet to enable you to direct the water where you want it to go. The backwash hose you purchase depends on where you plan on emptying the dirty pool water. You will want a hose that is long enough to reach your preferable dumping location. 

Check your pool’s water level

Before vacuuming your pool to waste, you will need to check your water level. Since the dirty pool water empties outside of the pool, you will want to run water into the pool with a hose while vacuuming. 

I normally top the pool up for a while before I start to vacuum to get the water level quite high as the water level will go down very fast when vacuuming on the waste setting. I normally get the water level to the top of the skimmer opening.

If you do not vacuum quickly enough, the water level may reach the bottom of the skimmer opening. If it falls below that then it is possible for the pump to run dry and become damaged. So before it gets to that point you should stop the pump and top the pool up again. 

Vacuuming your pool to waste

Vacuum a Pool to Waste

You should vacuum as you would when vacuuming on the filter setting, so switch the pump off if it is running, run out the backwash hose (if you have one). Move the multiport valve lever to waste and then switch the pump back on.

Now start to vacuum as you would when vacuuming on the filter setting.

However, as stated already, the water level will start to drop quite quickly so my advice would be to still move the vacuum head slowly, so as not to disturb too much dirt, but don’t be too particular about getting all of the dirt out. Just aim to get the worst of it out during this clean.

Inevitably you will need to vacuum again after the fine dirt you have disturbed settles again so you can just vacuum using the filter setting for the next clean.

I have a full article showing step by step how to vacuum a pool to waste which you may find useful.

How to reduce the need to vacuum to waste

You can reduce the frequency you may need to vacuum to waste by taking the following precautions:

  • Keep the paved/decked area around your pool clean by sweeping frequently to prevent any dirt, dust, leaves etc from blowing into the pool
  • If you have trees near your pool, particularly if they overhang, then keep any that drop leaves etc into the pool trimmed to try and reduce this
  • If you have a pool cover that you use in the winter, and know that a big storm is on its way, then consider covering the pool until the storm passes

When else to use the waste setting

The other time you may use the multiport valve on waste, without vacuuming, is if you have had heavy rain and the pool level is too high. Running the pump on waste for a while allows the water level to reduce to its proper level, ie. roughly half way above the skimmer opening.

Make sure you keep an eye on the level while this is happening as the level will go down quite quickly and you don’t want the level to drop below the skimmer.

Does my location determine when I should vacuum my pool to waste?

When to vacuum a pool to waste may be different depending on where you live. If you live in an area with lush foliage and lots of trees, you are more likely to get leaves, small branches, acorns, and the like in your pool.

Also, your climate and the weather where you live can have an impact. Learn the weather patterns in your area to help you develop your cleaning routine. 

Year-round use

If you are lucky enough to live in a climate that allows you to use your pool all year round, you should vacuum your pool to filter weekly and then vacuum to waste if lots of debris or algae exist. Even if your climate is good in the winter then you still may have to vacuum to waste more frequently than you would in the summer.

Monitor your pool for heavy debris and dirt to decide what routine works best for you. 

Seasonal use

For pools that get winterized and are only in use during the summer months, you will want to make sure to vacuum to waste directly before you winterize the pool and again as part of your pool opening routine in the spring.

When you are using the pool during the summer, you should only need to vacuum to waste when needed, not every week. 

Pool Care Handbook and Video Course

When I bought my house with a swimming pool, I knew absolutely nothing about pool care. I just winged it for a while, making many mistakes along the way.

Fortunately, I was recommended Swim University’s Pool Care Handbook and Video Course. I bought it and it was an absolute game-changer.

It was the best money I spent that year. I learned everything from basic cleaning to advanced troubleshooting. Swim University offers a no-quibble refund policy too so what do you have to lose?


Overall, a few different factors will determine when and how often you should vacuum your pool to waste. Make sure to keep an eye on the condition of your pool and perform regular cleanings. Not only will this reduce your vacuuming to waste frequency, but it will help keep your pool in better shape when it is not in use. 

I made the following video which you may find useful:

Read: My pick of the best pool vacuum heads

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