How Long Should You Backwash A Sand Filter

Backwashing clears out the dirt and gunk from your pool'due south filter. Whether you have a sand filter or a DE filter, information technology will need backwashing from time to fourth dimension. In this commodity I'll tell you why you need to backwash, when to backwash and give you stride-by-step instructions on how to backwash your pool'south filter.

To aftermath, a sand or DE filter, plow off the puddle pump and attach a backwash hose. Then prepare the valve to "backwash", switch the pump back on and allow the water menses out until information technology is clear (usually nigh 2 mins). You'll demand to next set the valve to rinse after for about 30 secs. If you take a DE filter, yous'll to refill the DE.

Of form, that was the extremely brusque version. In that location's more to it than that. In this article we cover inground pools, above ground pools, saltwater pools. In addition, yous'll detect these procedures will work for many brands, including:

Pentair
Intex
Hayward
Jandy
RX Articulate
Astral

Backwashing a pool filter. — Use the multiport valve to backwash the pool filter. Picture shows a fairly standard pool filter, pump and plumbing.

What is Backwashing?

Shows what backwashing is and how it works. The image on the left demonstrates regular filtering, the image on the right shows what happens when you backwash your pool. — The image on the left shows regular filtering. The dirty water from the pool comes downwardly through the sand, impurities are captured, then the h2o travels upwardly through the laterals and standpipe back to the puddle. Backwashing is the reverse (image on right). The pool h2o travels through the standpipe and out through the laterals at the bottom, so dorsum upwards through the sand lifting impurities. It then travels out through the waste outlet taking impurities and dirt with it.

Backwashing or backwash reverses the flow of water through the pool'due south filter, lifts upwards and flushes the filter medium (sand or DE), and and so expels the dingy water via a waste product line into the ground or drain. Sometimes this is also referred to equally backflushing.

Backwashing is essentially the procedure of cleaning the pool filter and needs to be done on a regular basis. More than on that later.

In club to ensure against residual blowback into the pool, once y'all've finished backwashing it is highly appropriate to rinse the filter. Simply every bit the aftermath lifts and flushes the sand, the rinse reseats the sand in its original position for optimum filtration.

Read on to learn how to aftermath your pool.

Why Should You Backwash?

All DE (diatomaceous earth) and sand filters use the same basic mechanics: when set to "Filter", water flows from the pool, through the filter, and back into the pool. The filter medium (sand or DE) inside the filter arrangement blocks debris, dirt, and oil. A typical pool filter multiport system has 6 different settings – Filter, Backwash, Rinse, Circulate, Closed, and Waste matter.

Nevertheless, over time, or when you vacuum your puddle, clay and debris get deposited in the filter – the upshot beingness that the filter becomes muddy and clogged with contaminants that, if left unchecked, will reduce the filter's power to clean and if left could restrict the h2o flow and put actress strain on the pool.

How to Aftermath a Sand Filter

Internals of a pool sand filter. — Diagram shows the internal workings of a pool's sand filter.

A puddle sand filter uses sand to take hold of contaminants in your pool's water. Pool water is circulated through special filter grade pool sand.

From time to time, y'all will need to clean your sand filter by backwashing it. Here's how to backwash a sand filter:

Plow off the pool pump.
Fix the sand filter valve handle to the BACKWASH pool position and ensure the handle locks in place.
Turn on the pump and aftermath for 2 minutes or until the h2o in the sight glass (located on the filter) is running clear.
Plow Off the Pump.
Set the filter valve handle to the RINSE position and ensure the handle locks in place.
Turn on the pump and run the rinse process for thirty-threescore seconds or until the water in the sight glass is clear.
Turn Off the Pump.
Close the skimmer valves to prevent h2o from entering the filter from the puddle. Empty the filter skimmer basket and clean out the hair catcher.
Re-seat and seal the skimmer handbasket and hair catcher.
Reopen the skimmer valves.
Reset the Filter Valve to Filter and ensure the handle locks into place.
Turn On the Pump.

How to Aftermath a DE Filter

Powder Diatomaceous Earth (D.E.) for DE Filters — Film shows Diatomaceous Earth or D.Eastward. which is the filter medium inside a D.E. puddle filter.

A DE filter uses Diatomaceous Earth (DE for short) instead of sand to grab contaminants. D.E. is a much finer medium than sand and therefore does a better task at filtering your pool water. However, at that place is some extra maintenance required when backwashing.

Backwashing a D.E. Filter is similar to a sand filter with one extra step of topping up the diatomaceous earth.

Of import: before you start, make sure y'all accept some D.East. powder on hand, every bit you'll need to pinnacle up the filter after backwashing. DE gets washed out when backwashing.

How to Backwash DE Filters (With Multiport Valves):

Switch off the pool pump.
Select the BACKWASH setting on the filter valve.
Turn the pump back on and backwash until for two minutes or until the water runs clear (y'all tin check this in the sight glass on the side of the filter).
Turn the pump off.
Select the RINSE setting on the filter valve.
Turn the pump back on and rinse for 1-ii minutes. You can repeat steps 2 to 6 a few times if the filter is particularly muddy.
Turn the pump off and select FILTER
Refill D.E. pulverization.
1. Check the manufacturer's instructions as to how much. Information technology will likely be three-6 lbs (or about lxxx% of the full capacity of the filter).
2. Usually you will add this to the skimmer (mix the DE with water first) and/or you'll add some D.East. powder in the pump strainer and the residuum in the skimmer. Again check the manufacturer'southward instructions.
3. Run the pump on the FILTER setting for 30 minutes or more to allow the D.Eastward. powder to coat the filter grids once again.

How to Backwash DE Filters (With Push-Pull Valves):

The backwashing procedure for DE filters with button-pull valves is almost the same as backwashing a DE filter with a multiport valve.

Switch off the pool pump.
Open the valve to Backwash.
Plow the pump back on and aftermath until for 2 minutes or until the water runs clear (you tin can check this in the sight glass on the side of the filter).
Turn the pump off.
Close the push/pull valve.
Refill the D.Eastward. pulverisation.
1. Check the manufacturer's instructions equally to how much. It will likely be three-6 lbs (or almost 80% of the full capacity of the filter).
2. Usually you lot will add this to the skimmer (mix the DE with water kickoff) and/or yous'll add some D.Eastward. powder in the pump strainer and the rest in the skimmer. Again check the manufacturer's instructions.
3. Run the pump for 30 minutes or more to permit the D.E. pulverization to coat the filter grids again.

Can You Backwash a Cartridge Filter?

Pool cartridge filters cannot be backwashed different their cousins sand filters and D.E. filters. Cartridge filters are not designed to run "backwards".

However cartridge filters can and should exist cleaned on a regular basis. To clean a cartridge filter yous'll need to open the filter up and remove the cartridge. Rinse and spray the cartridge with the hose every 4 weeks and give it a deep clean every few months.

Nosotros have full instructions to deep clean your cartridge filter in our blog here:
How to Clean Pool Cartridge Filter (Using Muriatic Acrid)

How Often to Backwash Puddle

As a rule of thumb, regardless of if you accept a sand filter or DE filter, yous should backwash your puddle most once a week during swimming flavour. The optimal time is correct afterwards you vacuum the puddle. If your puddle has had a lot more utilise than normal, information technology may exist necessary to backwash twice a week.

Nosotros recommend this suction cleaner and this robotic cleaner.

Also, if your pool is particularly prone to leaves, more than frequent backwashing may be necessary since leaves, other debris from copse, and contaminants from birds etc. will be entering your pool.

Yous tin can also tell when it is time for a backwash by checking the filter's pressure gauge. Normal operating pressures are between 50 and 170 Kpa (kilopascal) or x – 25 psi. When the sand gets dingy and clogged up, however, the pressure reading rises.

Typical pool filter pressure gauge. — When to backwash your pool? Use the filter pressure gauge equally a guide. It'due south time to aftermath when the pressure rises 8-10 psi to a higher place normal or above 80 Kpa.

If the pressure on the gauge is showing five-10 psi higher than normal, information technology'southward time to backwash.

If yous have already backed washed your pool and the pressure is withal high, bank check out our article: 8 Reasons Filter Pump Pressure is High (And How to Gear up)

When Not to Backwash

If your pool contains an unusually high level of dirt (for example, as a result of a nearby construction site, a protracted catamenia of existence untended and uncovered, or possibly from runoff acquired past flooding) it may exist appropriate to by-pass the filter entirely.

This is as well the case if your water had, or has had, an algae problem. Live algae easily pass through the filter sand and re-enters the pool. And the same goes for dead algae following a daze treatment. You can read more than on preventing algae here.

In these cases, instead of vacuuming and backwashing, it may be better to vacuum straight to WASTE, and to send the vacuumed water directly down into the drain.

Where to Get Rid of Backwash Water

When yous backwash your pool there will be quite a bit of water to deal with. Y'all need to have a plan earlier you lot outset. A few hundred gallons of water flooding onto your neighbors' properly volition likely event in y'all not existence invited to their adjacent Christmas party.

Your M

Disposing of pool aftermath h2o in your own yard is the recommended selection. Y'all'll find in many states and councils that it is illegal to dispose of pool water in the drain or sewer.

Make sure you proceed the water on your holding, though. Some councils upshot fines if poolwater runs off.

Will it kill the grass or plants? In most cases, your grass should be fine if y'all route your backwash water there. You may consider moving the hose around equally you are discharging the h2o, so the water doesn't accumulate in 1 spot.

Too, make sure it'south not going to run into your house or anywhere else.

As for plants, pool water volition impale some plants simply many of them will be fine, as long as they don't have as well much puddle water on them.

Gutter or Storm Drain

In many places, it's illegal to belch pool water into the street, gutter or stormwater drain unless it's been decontaminated. This water will frequently end up in rivers, creeks, lakes and oceans. Puddle water typically contains a range of chemicals that could be detrimental to the local environment.

Germ-free Sewer via Cleanout

In some areas, it's OK to dispose of pool h2o here. It's not normally OK to have your pool permanently plumbed into the sewer though. Check with your local council to observe out if this is an option for you.

Important Backwashing Tips

The one downside of backwashing is that, because h2o is expelled from the system and sent into waste, is that information technology…well…wastes water. While this is unavoidable, the key to non overdoing the backwash process and flushing out more than water than strictly necessary is to go along a careful eye on the colour and quality of the h2o in the sight glass.
Don't aftermath more than necessary, or for longer than necessary. Sand filter systems operate most efficiently during the middle of the filtration cycle. This is partly due to the positioning, at any given time, of the sand in the filter, and partly because of the cyclical build-upwards of collected dirt and droppings in the filter. The internet consequence is that too much or to frequent backwashing actually reduces the sand filter's efficiency.
Because backwashing inevitably washes out some of the sand along with the dirt and debris, from fourth dimension to time it volition exist necessary to top upwards the corporeality of sand in the filter. When you practice add extra sand, run the filter system on RINSE for a minute or so to reduce the amount of sand blowback into the pool. We recommend this replacement filter sand here.
Finally, absolutely make sure you always plough off the pump before you lot either motion or reset the filter valve setting. If you don't, you're going to damage, and perhaps destroy the system.

Recommended Products

Pool Sand Filter

Replacement Filter Sand

Swimming Pool Vacuum – Automatic Suction Cleaner or Robotic Cleaner

Related reading:

How to Get Sand Out of a Pool

Cloudy Pool Water: Why & How to Remedy