How To Change Sand In a Sand Filter

WRITTEN BY:  Inyo Pools

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Every 5 - 7 years you will have to replace the sand in your sand filter. The sand actually wears out. The sharp edges of the sand particles become worn and rounded and don't capture the contanimates as well. Also the sand will start to ball up or the water will create channels thru the sand. You will notice that your pool water is not as clean or the interval between required backwashes is shorter. This guide shows you the steps required to replace the sand in your sand filter.


Step by Step


Step 1

To change the sand in your sand filter you will have to remove the Multiport Valve on the top of your filter. If your filter was not installed with union connections, you will have to cut the piping to your filter. When you reinstall the filter after replacing the sand, this would be a good time to add unions.

Step 2

Before you start to change the sand in your filter, be sure to purchase any material or equipment you will need ahead of time. This might include sand, the O-ring between the valve and the tank, Teflon tape, lubricant, and unions. For the sand use only high rate No. 20 Silica Sand. An example is pictured at left. Check the manufacturer to determine the amount required. This unit (Hayward S180T) uses 3 50 lb bags of sand - 150 lbs total. You can also purchase our superior to sand Click here for our Sand Alternative.

Step 3

Before you start to change the sand, make sure you TURN OFF THE POOL PUMP. For maximum safety turn off the power at the circuit breaker to the pump.

Step 4

Next release the pressure in the filter tank by turning the drain cap at the bottom of the tank a half a turn counter-clockwise. Then remove the cap completely to drain the water out of the tank.

Step 5

Disconnect the waste hose that is attached to the "WASTE" line coming off the Multiport Valve.

Step 6

To remove the Multiport Valve unscrew unions that connect the piping to the "PUMP" and "RETURN" ports. If your filter does not have unions, cut the piping that connects these two ports. Be sure to leave enough room to attach unions later and stagger the cuts so that one union will not be installed on top of the other.

Step 7

Next take off the Multiport Valve flange clamp that holds the filter onto the tank. Screw off both bolts to separate the clamp. Keep track of the vinyl protector caps that are placed over the ends of the screws.

Step 8

With a gentle twisting motion, lift the valve off the pipe inside the tank. If you pull too fast or hard, you risk breaking the lateral pipes at the bottom of the tank.

Step 9

Tape the top of the pipe to prevent sand from entering and clogging the laterals.

Step 10

Remove sand carefully with a plastic cup until you can see the tops of the laterals at the bottom of the tank. If you have a wet and dry shop vac, it might be an easier and faster option to remore your sand.

Step 11

Gently pull the pipe and lateral assembly out of the rest of the sand. Then before you pull the assembly out of the tank, carefully rotate the 10 laterals up to the side of the pipe so that they will clear the hole.

Step 12

Lift the pipe and lateral assembly out of the tank.

Step 13

Check each of the laterals for breaks and replace as necessary. If the laterals are badly clogged you may want to soak them in a bucket of cleaning solution.

Step 14

Wash out the tank with a garden hose.

Step 15

Check the drain cap for cracks and replace it securely.

Step 16

Fill tank about 1/2 way full with water to provide a cushion when the sand is poured in. This will help protect the laterals.

Step 17

Next you will be replacing the pipe and lateral assembly back inside the tank. Make sure the 10 laterals are rotated up. Place the pipe and lateral assembly inside the tank.

Step 18

After the lateral assembly is inside, carefully rotate the 10 laterals 90 degrees in their down position.

Step 19

Make use the pipe is centered in the opening. Tape the top of the pipe to prevent sand from entering and clogging the laterals.

Step 20

The sand filter package came with a cardboard sand shield. If you still have this shield, place this over the pipe and within the opening. If not, you will have to take more care that the pipe remains centered when you pour in the sand.
.NOTE: Before you fill the tank with sand, line the tank up with the piping and do a trial install so you don't have to move the 300 # tank into place.

Step 21

Pour sand carefully into the pool sand filter until laterals are fully covered. For this unit 3 bags should leave at least 6" space between the top of the sand and the top of the filter. Level sand as you pour and make sure the center pipe remains centered in the opening. Be careful when leveling the sand that you do not lift the pipe and lateral assemble up off the bottom of the tank. You will not be able to push the pipe back down without causing the laterals to rotate up.

Step 22

Remove the O-ring on the bottom of the Multiport valve and check it for wear. Since you only do this every 5-7 years, it's probably a good idea to replace this O-ring now. Lightly lubricate the O-ring with a silicon lubricant and place it on the underside of the valve.

Step 23

Remove tape from top of pipe. Slip the Multiport control valve onto the central pipe - check the O-ring to ensure it is positioned correctly.

Step 24

Install clamp around the tank and valve flange. Tighten multiport valve flange clamp with a screwdriver. Tap around the clamp with the screwdriver handle as you are tightening the clamp to help seat the clamp properly. Place vinyl protector caps over the ends of the screws.

Step 25

Reconnect the two unions to the "PUMP" and "RETURN" ports. If you did not have unions, add unions now or glue the pipes back together with straight couplers.

Step 26

With the pump OFF, depress the multiport valve handle fully and turn it to the "BACKWASH" position. Make sure that your waste line is rolled out to where you want to dump the pool waste water.

Step 27

Prime and turn ON the pool pump. Be sure that you have at least one suction and all discharge lines open.

Step 28

Run the pool pump for 2 minutes after you have a steady flow of water out the waste line (after the pump is fully primed). This will flush all the impurities or fine sand particles out of the sand media.

Step 29

Turn the pool pump OFF and turn the valve handle to "RINSE".

Step 30

Turn the pump back ON and run until the water in the sight glass is clear. This should take no more than 1 minute.

Step 31

Turn the pool pump OFF and turn the valve handle to "FILTER".

Step 32

Turn the pool pump ON. This is the normal operating mode for your filter. Note the pressure gauge reading. This is your clean sand filter pressure.


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Inyopools  Posted: 12/27/2017 14:48 PM  Inyo Product Specialist

Susanne - If you have unions on the pipes to your filter, or if you have an above ground setup, you could change your filter sand in an hour or two.

Susanne  Posted: 12/21/2017 3:35 AM 

How long should it take to undergo this procedure?

Inyopools  Posted: 11/02/2017 10:08 AM  Inyo Product Specialist

Deryk - If your laterals are that high up off the bottom, you are losing a large part of your filtering capacity. Check the parts list for your filter. The length of the standpipe will vary with the size of your filter by 7". And I would use any sand that is labeled for filter use.

Deryk  Posted: 10/26/2017 13:07 PM 

Great instructions. I am a new pool owner and decided that I would change the filter sand while I have it winterized. I am glad I am doing it but I have 2 questions. First, the pipe and laterals in my filter were no where close to sitting on the bottom of the filter, more like 10 inches from the bottom so about 10 inches of sand below and above. Setting it on the bottom will leave the center pipe about 10 inches short. Is it fine to reinstall the same depth or should I make the center pipe longer? Second question, is all filter sand the same or do I need to find a certain coarseness? I have seen different options and confused about which to go with. Thanks.

Inyopools  Posted: 10/12/2017 11:36 AM  Inyo Product Specialist

Jethro - Try using WD40 on the screws and tap them gently with a screwdriver and hammer to loosen them up. Your filter gauge will typically read between 10 - 15 psi after changing the sand.

Jethro  Posted: 10/07/2017 17:19 PM 

Hello Bllinger. Thanks for the site's info. I've moved into a house with an existing pool and so am learning everything from scratch. I doubt whether the sand have ever been replaced and the pressure guage is so old and worn, it's unreadable and most likely does not work. I need to replace the sand (thanks for the steps to do this) but the screws holding the cover are not able to undo so I'm thinking I will have to cut these and get new screws?
I will get a new guage too and when I do, what pressure should it ideally read? Thanks

Inyopools  Posted: 07/19/2017 10:44 AM  Inyo Product Specialist

Tarner - If you are unsure of the age of the sand, try replacing the top 6" and see if that helps. If not, I would replace all of the sand.

Tamer  Posted: 07/17/2017 15:50 PM 

Hello, The gauge on my filter reads 19-20 PSI with or without backwash, the sand in the filter is probably 3 years old as I have a sticker on the filter that shows 2014 ( I am new to the house)...I have had recommendation from my chemical supplier to change the sand as I have been told the pressure should be around 10 PSI...would this make sense?...

Inyopools  Posted: 07/13/2017 10:35 AM  Inyo Product Specialist

Jessica - Many people use a screw extractor method. Here is a link to a video on "How to remove a damaged screw with a broken screw extractor".

Jessica  Posted: 07/11/2017 16:33 PM 

Great guide! Our laterals were not the rotate up kind, ours twisted off the pipe one at a time. Our only problem was one of the screws holding the clamp on was Stuck! No amount of WD40 or elbow grease budget it. Our local pool store said there was no way to get it loose, we'd have to cut it. We have a rotary cutter so that made it easy, although it did melt the plastic some. Got it back together ok but it was very tough. We will have to replace the clamp next time we change the sand for sure! Any tips for removing stuck screws like that?

Inyopools  Posted: 07/10/2017 11:58 AM  Inyo Product Specialist

Dan - Your problem is probably related to what you did when you changed your filter's sand. Go back through the process again. Look for actions that could have blocked return flow. I don't think you have to actually take the sand out but check the rest of the process against the guide. Did you shut off any return diverter valves? Did you leave at least 6" between the top of the sand and the top of the tank? When you shut off your pump, do you get a backward surge of water from the filter to the skimmer? This would indicate a suction air leak before the pump. Check that the O-ring on the pump's strainer cover is good and not causing a suction leak.

Inyopools  Posted: 07/10/2017 11:01 AM  Inyo Product Specialist

MKitch - Give us a call at 407-834-2200 and talk to one of our service reps. The service rep will probably ask for a picture to identify the filter.

Dan  Posted: 07/09/2017 8:45 AM 

Hi. We just changed the sand in our filter. After some back wash and rinse we try to start the pump with the ordinary filter function. But the pressure increases way to much.and the water is leaking out from the top. It wasn't like that before. Do you have any idea what.could be.wrong?

MKitch  Posted: 07/08/2017 12:50 PM 

My sand filter has 2 labels on the outside which are faded past being legible. How do I tell what sand filter I have? I have been in my house 6 years and would like to replace the sand.

Inyopools  Posted: 06/26/2017 12:29 PM  Inyo Product Specialist

Birdy - No, I would not change the sand again. Just backwash and rinse it a couple of time to remove any impurities.

Birdy  Posted: 06/24/2017 6:33 AM 

I put sand in my fikter. Ran it for three days.i had magnesium in my water...I drained the water got new water...Sand is 3 days old.. should I change it after running that nasty water in it?

Inyopools  Posted: 06/22/2017 11:21 AM  Inyo Product Specialist

bollinger - If you haven't changed your filter sand in 6 years, I would do that now. Sand loses its ability to filter after 5-7 years. If you see no improvement, see our guide on " How To Go From Cloudy To A Crystal Clear Pool".

bollinger  Posted: 06/20/2017 15:45 PM 

I had my sand changed 6 years ago, but this year we have battled cloudy water. I've done everything except change sand. Is this usually the next step short of throwing dynamite it?

Smellis  Posted: 06/18/2017 16:34 PM 

Thanks for the step by step instructions... It was easy to prepare for and follow. It took less than 2.5 hours and my pool was back up Ann's running.

Anonymous  Posted: 06/15/2017 18:33 PM 

Great instructions

Inyopools  Posted: 06/12/2017 12:00 PM  Inyo Product Specialist

Anonymous (changing sand) - I would guess that your sand filter is not your problem. You may have low water flow. Check for a clogged impeller. See our guide on "How To Clean Out a Pool Pump Impeller". If that is good, you may need to be more persistent with shocking your pool  See our blog on "How to Clean a Green Pool".

Anonymous  Posted: 06/10/2017 9:15 AM 

My husband replaced the sand in our filter a few weeks ago, but I don't think he rinsed the sand to waste before turning the filter on. Our water looks terrible after 2 weeks of chemicals and running filter non-stop. Could this be the problem? Also, we added sand just based on the number of lbs it needs and going by the number of pounds per bag of sand. Is this right or should we be going by the actual sand level in the filter? Thanks. It's mid-June and we haven't been able to get in our pool yet, so are very frustrated - help would be appreciated.

Oz  Posted: 06/09/2017 22:04 PM 

Very helpful thank you for your time

Justincredible  Posted: 06/04/2017 20:48 PM 

Thanks for the simple, yet thorough, instructions. Just the right amount of information for a novice like me to follow along and not screw anything up! Had my previous home owner installed unions this project would have been quicker. At least now they're installed so next time there'll be no cutting or pvc cement involved.
Thanks again!

Inyopools  Posted: 06/01/2017 12:55 PM  Inyo Product Specialist

Anonymous (no flow) - Even if one lateral was up, that should not prevent flow. With an above ground pool, your pump does not have to pull water from the pool. Water will fall from the pool to the pump at the bottom of the pool through gravity. So it the tube between the pool and the pump is open, you shouldn't have a problem there. Now the pump has to push the water through the filter. Check to make sure your pump's impeller is not clogged. If the impeller is clear and the tube to the top of the filter is clear you should be getting water into the top of the filter. Now check the spider gasket in the filter's multiport valve. If it is damaged, it may be blocking flow out of the filter. Generally, though, you would have flow, it would just be going out the wrong port.

Anonymous  Posted: 05/29/2017 10:47 AM 

I have a Dream line high rate sand filter .I had to take the pool down for because we moved .I bought the pump last summer worked wonderful , put it back together did everything it said in the instructions it wont suck the water from the pool and it dont have any pressure. If one of the laterals are not flat at the bottom could this be the problem. The pump is coming on and sand tank is filled with water and the scimmer has water no line are blocked or clogged

Topher  Posted: 05/26/2017 13:37 PM 

This is well done and very user friendly. Thanks for taking time out to provide this for everyone. Kudos and God Bless.

Inyopools  Posted: 05/15/2017 14:11 PM  Inyo Product Specialist

Gary - No, your pool does not have to be filled up to normal operating level before you change your filter sand. But you will have to fill it before you turn on your pump so the pump will prime.

Inyopools  Posted: 05/15/2017 11:31 AM  Inyo Product Specialist

glenncz - Good point and thank you for your input. I will incorporate your comment into our guide.

Gary  Posted: 05/15/2017 10:58 AM 

Do my pool need to be filled up to the normal pool level before I can change the sand.

glenncz  Posted: 05/13/2017 19:34 PM 

Article was super helpful for amateur first time sand change. But you left one super impt thing out!!!! I got to the point of washing the filter out and emptying it on side. Then I hosed/cleaned pad and "sort of" put it back where it was. Of course after putting 300 lbs of sand in it the hoses didn't line up. i think good advice would be to do a dummy fit of cap and hoses to make sure filter is back in same spot and much easier to move it empty. Then fill it up with sand.

Bradwho  Posted: 03/13/2017 17:00 PM 

My in ground pool is only 3 years old, last year I installed a heat pump. My problem is that my filter develops too much back pressure and shuts down my heat pump after only a few days from backwash. I backwash and rinse again, and it works fine for a few days then shuts off again. My question is my sand already bad?

Anonymous  Posted: 08/15/2016 20:13 PM 

Awesome guide, thank you. Much easier than I thought it might be. This was the answer to weeks of cloudy pool water and endless chasing of chemicals. My filter was about 7 years old. I overpaid on Amazon prime for #20 silica sand but got it in 2 days and it arrived while I was already taking the multi port valve off.

Inyopools  Posted: 07/19/2016 18:06 PM  Inyo Product Specialist

Edwin - Check the spider gasket in you multiport valve to make sure it is not damaged and letting water into the wrong ports. Then remove the sand in your filter and check for cracks in the laterals, the lateral hub, and the standpipe.

Edwin  Posted: 07/17/2016 8:00 AM 

When I vacuum my pool, some of the dust comes out of the jets even though I backwash four or five times.

Inyopools  Posted: 06/01/2016 12:57 PM  Inyo Product Specialist

C-Ray – I’m assuming that you have a Waterway Carefree Sand Filter that looks like this. Waterway bought out Proline. To determine the diameter of the filter tank, take a string and measure around the circumference of the tank at its widest point. Divide that measurement by 3.14 to get the tanks diameter. If it is 22" you will need 150 lbs of sand. If 26”, you will need 200 lbs of sand.

C-Ray  Posted: 05/31/2016 16:42 PM 

Great article. Very thorough and helpful. One question- how can I figure out how much sand to use in my filter? It's a Proline sand filter from 2007. Label on the filter is worn out and tattered. No clue on the model number. Only thing I can make out is P25121 on the label, but my internet search shows nothing related. I'm guessing the filter is a 22 or 26 inch

Lori  Posted: 05/29/2016 8:37 AM 

My husband changed the pool filter sand as instructed with no issues, and when he was finished he first attempted to backwash. Nothing happened. No water came out of the waste line at all. What could be the issue?

Inyopools  Posted: 05/04/2016 12:16 PM  Inyo Product Specialist

Princess - Some sand has very fine sand in the bag that gets through the laterals. Try vacuuming up the existing sand with a suction vacuum. If you get more sand, you may have a broken lateral or standpipe which means taking the sand out again to inspect the pipes.

Princess  Posted: 05/02/2016 17:17 PM 

Changed sand in my filter now we have lots of sand in the bottom of our pool. What did we do wrong?