How To Change Sand In a Sand Filter


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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 contaminates as well. Also, the sand will start to ball up or the water will create channels through 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 pool filter.

Click Here to View our Available Sand Filters

Click Here to View Replacement Sand Filter Parts 


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.

Please Click Here to View Multiport Valves

Please Click Here to View 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.

Please Click Here to View ZeoSand Alternativet

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.

Please Click Here to View the Backwash Hose

Please Click Here to View Hose Clamps

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.

Please click here to view multiport valves.

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 remove 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 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.

Please click here to view multiport valves.

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 silicone lubricant and place it on the underside of the valve.

Please Click Here to View Magic Lube O-Ring Lubricant

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.

Please Click Here to View Diverter Valves

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".

Click Here to View our Available Sand Filters

Click Here to View Replacement Sand Filter Parts 

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.

Please Click Here to View Pressure Gauges


(1 to 40 of 158)

 Posted: 7/25/2020 

I was wondering, after you finish adding the new sand to the filter, do you fill the rest of the filter with water? I saw another site say to do so, but these instructions seem to leave that out. Which is correct? Thanks.

InyoPools Product Specialist  Posted: 9/3/2020 

You can do that. Another tip, before adding sand, fill the tank halfway with water, it will help prevent laterals from cracking as you pour hundreds of pounds of sand onto them.

 Posted: 6/5/2019 

Does it matter if your sand filter directions say to fill half the tank full of water then put the sand in it. If you do it in reverse does it matter?

InyoPools Product Specialist  Posted: 6/6/2019 

Part of the point to adding the water before the sand is to soften the blow the laterals take when you pour hundreds of pounds of sand onto them. If you do not do it this way, there is a higher chance of busting a lateral; which means you have to remove all that sand to repair it.

 Posted: 5/31/2019 

Is there any benefit to replacing just the sand that's above the laterals? We just bought s house with a 20x40 pool with a Hayward sand filter. Not sure when it was last changed. Seems simpler to get the multiport off and just empty enough sand down to the laterals, then replace that amount, than do the whole tank right now.

InyoPools Product Specialist  Posted: 6/6/2019 

 That old dirty sand is going to be jumbled up and mixed with the new sand during backwash cycles, so it is going to put your sand age back a step from the get. If you are going to take the time to dig out 185 pounds of sand, why not just get out the last 20 or so? 

 Posted: 11/14/2018 

Hi JKM, I find that the bottom of my pool gets covered in dust / fine sand within 2 days of a clean. Based on comments in here I have checked all the laterals and downpipe for damage but all seems ok. Is there any other potential problem? I have a Astral E650 media filter, which looks like it is no longer available. It came with the house. ( I have also recently replaced the sand) Your help is really appreciated. Thanks James

InyoPools Product Specialist  Posted: 11/27/2018 

Hello James - is your pump and filter draining when the pump turns off? If so, sand could be backwashing from the filter and pump, then through to the skimmer and main drain. This is a commonly seen with DE filters as well.

 Posted: 9/18/2018 

Hello JKM - using the waste port in that way is not possible because the valve plumbing routing is not designed to do that. The waste option is only for water disposal. The spider gasket is included on key 9 on this parts listing: Pentair - Pac Fab Top Mount 1 1/2" 26-1124, 26-1130, 26-2506

 Posted: 3/19/2019 

Clarification- While the step seems to say WASTE, the previous step says to turn to BACKWASH.

 Posted: 9/16/2018 

Why can't I pump the sand out of the tank by using the waste port selection on the top mount unit? What is the O ring reorder number for my SD 80 Pentair?

 Posted: 9/12/2018 

Hello Geoff - It sounds like you may have a cracked lateral or standpipe. Unfortunately, those parts are no longer available for the GM-245. You'd want to look at a complete replacement when the time comes. We'd recommend something like the Hayward S244T.

 Posted: 9/10/2018 

Recently I'm seeing a small amount of sand in each backwash waste cycle (once per week) and I'm unsure of what's causing it. It's a 25 year old Hayward GM-245 filter and the sand was replaced about 10 years ago. No pump change or pressure change has occured and it has been working well up until now? Do I have a bad lateral? Am I better to replace the entire sand filter given it's age or can I even get a replacement lateral?

 Posted: 8/20/2018 

Hello Phil - a raise of 1-2 PSI on a 25-year-old filter is nothing to be concerned about. As we say in other comments, PSI for each pool is different from pool to pool. Comparing PSIs between pools is an apples and oranges situation. But if the filter was working fine for almost 3 dacades then there is nothing to be concerned with.

 Posted: 8/19/2018 

Are the inyopool comments on pressure specific to a given filter?: I have read/heard various opinions on pressure readings after changing sand, with the most common guideline being that your baseline will be the initial reading (assuming the installation is correct). My Tagelus filter holds 250 lbs of sand. When it was first set up by my installer 25 years ago, the baseline reading was 26 psi. I just changed the sand (correctly, thanks for the excellent guidelines) and my new reading is 27-28 psi. This did not concern me until I saw the numbers (as low as 10-15 psi) quoted here. Do I have a problem?

 Posted: 8/16/2018 

Hello Joanne - If water is bypassing the filter and returning to the pool when the valve is set on backwash, you may have a bad spider gasket. I would open up the valve and check that gasket first. After that, you'd want to possibly replace the sand or standpipe/lateral assembly.

 Posted: 8/10/2018 

I have a problem. No matter what setting I have my valve on, the water seems to go back into my pool. It’s so cloudy and even when I vacuum, it’s dirty again the next day. Do you think this is a sand problem or is there another reason that the water could be bypassing the sand. I am wondering if it could be the valve cracked.

 Posted: 7/18/2018 

Hello Don - You can move the the standpipe back and forth until it lowers enough for the valve to fit correctly. If that doesn't work, you'll need to remove the sand and reinstall the standpipe.

 Posted: 5/27/2018 

Thanks for the great instructions. I'm in the process of changing my filter sand and I've just completed pouring the new sand in. It looks like my standpipe is sitting about 1/2" too high to get the valve back on correctly. I assume some sand is sitting under the laterals. Is there an easier way to fix this than removing all the sand, re-seating the standpipe and then putting the new sand back? Thanks!

 Posted: 3/21/2018 

If your laterals only have slot openings on one side, they should be facing down.

Anonymous  Posted: 3/16/2018 

When replacing the laterals do the slot opening go up or down to the bottom of the filter

 Posted: 12/27/2017 

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.

 Posted: 12/21/2017 

How long should it take to undergo this procedure?

 Posted: 11/2/2017 

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.

 Posted: 10/26/2017 

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.

 Posted: 10/12/2017 

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.

 Posted: 10/7/2017 

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 Product Specialist  Posted: 7/19/2017 

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.

 Posted: 7/17/2017 

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 Product Specialist  Posted: 7/13/2017 

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".

 Posted: 7/11/2017 

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 Product Specialist  Posted: 7/10/2017 

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 Product Specialist  Posted: 7/10/2017 

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.

 Posted: 7/9/2017 

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?

 Posted: 7/8/2017 

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 Product Specialist  Posted: 6/26/2017 

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

 Posted: 6/24/2017 

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 Product Specialist  Posted: 6/22/2017 

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".

 Posted: 6/20/2017 

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?

 Posted: 6/18/2017 

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.