Changing Sand in Pool Filter: Ultimate DIY Guide

Do you have a sand filter for your swimming pool that seems like it’s not quite doing its job anymore?

Have you noticed your once-clean pool turning murkier every day?

Is sand making its way into your pool, or have you started to notice a strange slimy feeling or a bad smell coming from the water?

If any of these problems are happening to you, it’s probably time to think about replacing pool filter sand in your filter tank.

When you first set up your pool filter, you probably thought it was going to be a long time before you’d need to worry about putting in any new sand. And if your filter has been working properly, it probably has been a while! But now it’s time to learn about removing sand from pool filter tanks and how to replace it with fresh, clean sand that will last you several more years.

In this article, you’ll learn a few tips to help you better understand when it’s time to change your sand. After that, you’ll be introduced to all the materials you’ll need to get started. From there, you can find our simple step-by-step guide, separated into each part of the process to make it easier than ever for you to learn how to change pool filter sand on your own.

By the time you’ve finished reading our article, you’ll feel like a pro at taking care of the sand in your filter tank. So what are you waiting for? Read on to learn more about how you can take care of this important maintenance on your own without ever having to call a pool tech.

Why Change Your Sand?

Some pool owners swear by the idea that the sand in theirc should never need to be replaced. Others believe it needs to be changed every year just like any other type of filter media should be. The way you use your pool filter is entirely up to you, of course, but there are plenty of good reasons why you might want to change your pool sand every now and then. Check out the list below to help you figure out whether or not these reasons are right for you.

 pool filter sand

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  • Some people believe the dirtier the sand, the better it is for cleaning your pool water. This belief stems from the idea that more dirt particles in the sand will work as additional filtration and will, therefore, remove more contaminants from the water before it hits your pool. Of course, it might sound a little gross to use dirt to filter your pool, and it’s a good idea to keep in mind how contaminated the sand gets when it sits in your filter for years and years without cleaning.
  • Others believe that sand in your filter should be dumped out every year and replaced with entirely new sand annually. This is a little too far on the other end of the spectrum in terms of filtration extremes, however. There is something to be said for leaving your sand where it is for a little while and allowing it to build up a strong resistance to contaminants in your pool water.
  • The best way to go about this is to try to find a happy medium. Your sand should usually be replaced every three to five years to prevent a lot of very nasty contaminants from taking hold inside the tank while still giving the sand plenty of time to do its job.
  • One of the biggest reasons why you should still think about changing your sand even with other pool owners might not is the cleanliness of your water. While swimming in murky or foul-smelling water is unpleasant, the real threat lies with potential bacteria that could build up inside your filter tank over time. Keep yourself and your family safe by making sure your filter sand stays as clean as necessary for as long as possible.
  • You can also extend the life of your filter significantly by replacing the sand every few years. When you leave old, dirty sand in place for more than five years, you’re asking for trouble with your filter. It will have to work overtime to take care of the water that passes through the media, and after a while, it’s sure to go out, break, or otherwise cause a problem.
  • On the other hand, if you’re replacing your sand every year, you’re disturbing a filter that’s working fine just the way it is. Leave it alone for a few years unless an issue arises. That way, you won’t have to worry about potentially breaking any internal pieces or replacing any external parts that might get worn out with frequent changes.

When to Change Your Sand

sand change

Understanding the right time to change your pool filter sand is an important first step before you ever get started on the actual cleaning and changing process. Keep the following few tips in mind to help you remember when it’s time to think about new sand.

  • Keep track of how long your current sand has been in the filter. Most sand will need to be replaced every three to five years. Sometimes, sand can last much longer.
  • If your water is very dirty, if your pool operates all year long, if you have very hard water, or if you use your pool several times a week every week, you may need to change your sand every one to two years.
  • When sand starts to drift into your pool, it may be time to change the sand in the filter. Filter sand stops working correctly when it begins to form tunnels that water can wash right through. As this happens, the water usually carries sand grains with it into your pool.
  • If your water is looking murky, cloudy, or a strange color, it might be time to change your sand. Algae in your pool may also be a sign that you need to think about some fresh sand, too, although algae may occur from other reasons as well.
  • You do not have to change your sand every time you backwash. On most modern filters, you won’t even have to add any sand back into the tank at all during a normal backwash. Every now and then you may need to add a scoop or two to even out the pressure in the filter tank.

Once you’ve determined that it’s time to do some cleaning and change your filter sand, you can start gathering your materials and prepare to take the next step toward getting rid of your old sand.

PLEASE NOTE!

Disposing of old pool filter sand can be complicated. If possible, do not dump it into your yard where contaminants from the water can seep into the groundwater. Dispose of it carefully and properly to help protect your home and the environment.

Equipment and Materials Needed

In this section, you’ll learn all about the different types of materials and equipment you’ll need to change sand in pool filter tanks. The type of filter you have may change this list somewhat, but we’ve made sure to mention everything you might need so you can be more than prepared when the time comes. Keep everything close by during the sand changing process so you won’t have to walk away and leave any potentially dangerous tools or equipment unattended. Changing sand in pool filter tanks isn’t a dangerous task, but it always pays to be mindful of where your tools are and what you’re doing!

equipments needed
  • Shop vac – You don’t necessarily have to have one of these, but it will make removing the old sand from your tank much safer and easier, too. Shop vacs are sold in most home improvement stores as well as some big box stores. With this task, you’ll be using yours to remove all the old sand from the filter tank, and you will then need to empty out the shop vac to safely dispose of the sand inside.
  • Small plastic cup or scoop – If you don’t have a shop vac, you’ll have to remove the sand by hand. It’s going to take a lot longer, but that doesn’t mean it’s impossible. Have a plastic cup handy, or use a scoop that’s small enough to fit inside the tank but large enough to remove a decent amount of sand with each scoop. You may still need one of these items to remove any stray sand that your shop vac can’t reach, too.
  • Large plastic bucket or tub – This is optional, but it can be very handy for tossing out old sand or for washing the internals in your filter tank. Any plastic bucket or tub will do. You may be able to find these at home improvement stores or you might have an old one left over from some other product you’ve recently purchased.
  • Gloves and a face mask – The old sand in your filter tank is dirty and full of contaminants. You didn’t want those contaminants in your pool water, so why would you want them to touch you now? For your safety, be sure to wear gloves and a mask when handling the old sand. It’s a good idea to at least keep the mask on when handling the new sand, too, just so you don’t breathe in too much dust as you’re pouring it. These items can be found in just about any store.
  • Garden hose – You’ve probably already got a garden hose, but if you don’t, be sure to pick one up before you get started on this job. You’ll need to rinse out the inside of your filter tank, and you’ll also want one handy to help you wash down the internal pieces of the filter too. This is arguably the most important piece of equipment you’ll need to get this job done!
  • #20 silica sand or alternative – Pool sand filters are designed to take #20-grade silica sand. Most modern filters can also be used with sand alternatives, like ZeoSand or Filter Glass. These are great options if you’re looking for something a little more environmentally friendly, but if you stick to traditional pool sand, that’s okay too. Be sure to have plenty on hand to refill your tank before you start cleaning.
  • Replacement o-ring – Depending on your filter, you may or may not need this piece, but it’s handy to have it around just in case. Some filters close with a locking mechanism and a gasket that’s surrounded by an o-ring. As you clean and maintain your filter, you’ll have to open this gasket, and the o-ring will stretch out over time. You can save yourself a lot of trouble with leaks in the future by replacing the o-ring each time you replace the sand if your filter requires it.
  • Dish detergent – You may need a few drops of dish detergent to soak the internals of your filter tank, depending on how dirty or grimy they are. If they’re not very dirty, you won’t need this, but it never hurts to have some nearby when you’re cleaning pieces of your pool filter. 
  • Wrench – You may need a wrench to remove the filter tank from its base or from the hoses that are attached to it. You may also need it to help open the filter tank and get it closed again when you’re finished.
  • Screwdriver – You may need a screwdriver to open your filter tank to access the sand inside. You may also need it to help remove the internal pieces of the filter tank, but on most newer models, these should be able to be removed by hand.

A note on dish detergent: Be absolutely sure the suds and soap are completely washed off of any pieces of your filter before you put it back together. Otherwise, you’ll have suds and foam in your pool!

A note on sand amounts: Your filter should have a label or a stamp somewhere on the tank that lets you know how large the tank is. It should tell you, in gallons, how much sand it holds. If it doesn’t, your instruction manual will tell you. If you no longer have that on hand, you can look up the make and model of your filter tank online to find out how many gallons of sand you need to fill it with.

How to Change Your Sand

Now it’s time to get started changing pool filter sand. Check out the video above to get a visual idea of how to do this first then you can use the steps below for further information.

Each of the steps in this process is outlined below and separated into a different section. This way, if you find the need to take a short break at any point, you’ll be able to pick up right where you left off. This is also a helpful way to be sure you stay on track and don’t jump ahead to a section you’re not quite ready to work on yet. Let’s get started!

How to Begin

1. Start by assembling all the parts listed in the section above.

Make sure to have everything close by while you’re working so you won’t have to step away or go searching for something.

turn off the filter

2. Next, turn off your pool’s filter and pump. 

Depending on the type of pool you have, you might have to go about this in one of several ways. The best way is to look for an on/off switch on the filter and pump. If you can’t find one, you can always just unplug the filter and pump from their power source.

SAFETY FIRST!
  • This isn’t an electrical task, but it still may be much safer if you turn off the breaker that controls your pool while you’re working. This way, no water will splash onto any exposed electrical areas and you’ll be much safer overall.
  • Although you aren’t required to turn off the breaker, it can also help prevent any damage that might occur to your filter or pump if a valve should get turned to the wrong position or either piece of equipment should accidentally be turned on while you’re cleaning.

3. Head back to your filter tank and look for the multiport valve on top of the tank.

 It may also be located on the side on some older models. You’ll need to remove this before you can get to the sand inside the tank. The following steps will explain how to do this.

4. Turn the drain cap or valve on the side of the filter tank counter-clockwise or until the pressure in the tank is releasing.

After the pressure has released, you can remove the cap or open the valve completely to continue working.

How to Open the Filter

1. There should be several hoses attached to your filter. 

garden hose

For the next step, you’re looking for the waste hose. The multiport valve should direct you toward the hose intended for waste. This hose is probably attached to a pipeline that may be attached to either your pump or your filter.

2. Disconnect the waste hose before you try to remove the multiport valve.

3. Repeat this process to disconnect the pipes or hoses that are attached to the pump and return portions of the valve.

  • You may have an older filter tank that doesn’t have screwing mechanisms (unions) to help make disconnecting these pipes and hoses easy. If not, you’ll need to cut your pipelines.
  • You can very easily install unions after cutting your pipelines to help make this step simple and quick in the future.

4. Unscrew the bolts that hold the multiport valve’s clamp in place.

unscrew bolts

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This should loosen the valve considerably. Be careful not to lose the screws that hold this valve in place, as you will be unable to run the filter without it installed properly after you’re finished.

5. Carefully remove the multiport valve from the top of the tank.

You may need to lightly twist the valve to get it to come away from the tank itself.

  • Remember that this valve is attached to pipes at the bottom of the tank as well, so it pays to be cautious when removing it.
  • If you remove the valve too quickly, you may break the pipes that run throughout the rest of the tank. If this happens, you’ll have to put your pool usage on hold until you can repair or replace the damaged pieces.

How to Remove the Old Sand

The easiest way to remove the sand inside your tank is to use a shop vac. To do this, simply plug in the shop vac nearby and use it on its lowest setting to suck up all the soggy sand inside the tank. When you’re finished, just empty out the shop vac like normal and safely dispose of the sand. You may also want to rinse out the inside of the shop vac when you’re finished to prevent the sand from clogging any of the pipes or hoses attached to the vacuum.

shop vac

https://www.youtube.com/watch?v=JgAL_rDn190&t=10s

6. If you don’t have a shop vac or if you don’t want to use one, you’ll need to remove the sand by hand.

The first step is to cover up the exposed vertical pipe that should be visible once you remove the multiport valve. It’s very important to prevent sand from getting into this pipe because it’s connected to the laterals that make the filter and pump work. If sand does get into the pipe, you must remove it before you continue using the filter, and that can be its own challenging job.

  • The best way to cover this pipe is to simply use a little duct tape. If you don’t have duct tape handy, you can use a rubber band to affix an old towel or washcloth over the pipe. Anything you have available that can cover the hole in the pipe will do the trick.
remove sand

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7. If you aren’t using your shop vac, get your plastic cup and plastic bucket or tub.

You’ll need to remove the sand one scoop at a time and dump it into the plastic bucket. Be sure to put on your gloves and face mask before you do this so you don’t have to come into direct contact with sand that is contaminated with bacteria and much more.

8. When you’ve exposed the laterals on the bottom of the tank, you can stop scooping.

Carefully grasp the central pipe and gently pull the pipe and laterals up and out of the sand. Once again, be cautious so you don’t break any of these pieces.

  • If the central pipe pops out of the attachment at the base of the tank, you’ll need to cover the base with duct tape as well.

9. You may need to fold the laterals up a little bit to allow them to clear the entrance to the filter tank.

Most newer sand filter laterals will be hinged so that you can do this easily. On older models, it may take a little repositioning to figure out the right way to remove this piece without causing any breaks or other damage.

How to Clean the Internals

1. Look over the laterals carefully to see if they have any damage, breaks, or weak points.

check for breaking points

This is a great time to replace any damaged pieces to your filter or to take note of any problem areas you might want to check up on again in the near future. Don’t forget to look at all sides of this piece of your tank, since this part is crucial to the functioning of your filter.

2. After you’ve inspected and repaired or noted anything that needs your attention, place the laterals in your large plastic tub or bucket.

  • If you used this piece of equipment already to remove your dirty sand, dispose of the sand carefully and safely and then rinse out the bucket completely with your garden hose before adding the laterals.
  • Once the laterals are inside the bucket, fill it up with your garden hose. You probably won’t be able to completely cover the central pipe, but you’ll be able to cover the folded laterals from the bottom of the filter tank. Use slightly warm water if possible, but if not, it should be fine.

3. Add a couple of drops of dish detergent to your bucket and let the laterals soak for a while. 

 If they’re very grimy or have a lot of caked-on calcium buildup from hard water, you might need to purchase a more powerful chemical cleaner. However, for most situations, dish detergent should be strong enough to remove most of the grime that this part of your filter may accumulate over time.

dish detergent

4. You can let this piece soak while you move on to the next part of the sand replacement process, or you can wait for the laterals to be finished soaking before you go to the next step.

  • Either way, when they’ve soaked for a little while, take them out of the bucket and rinse them off thoroughly with your garden hose. Be sure to focus on any areas where the grime might still be stuck on.
  • If you’re having trouble getting all the dirt off of your laterals, wipe them down with a clean rag or towel.
wash inside of tank

5. Use your garden hose to thoroughly wash out the inside of your tank.

Be sure to remove any remaining sand that might still be inside and dispose of it properly. Give it a couple of good rinses and dump out the water before you continue.

  • It’s okay if a little bit of sand gets left behind in some of the harder to reach portions of your filter tank. The point here isn’t to remove every single grain, but to get as much of it out as possible.
  • If you used a shop vac to remove the sand, you may still need to do this step by hand depending on the size of your filter tank. It may be difficult to maneuver a shop vac around to reach some parts of your filter.

How to Fill the Tank

1. Replace the drain cap that you removed earlier when you released the pressure inside the filter tank. 

If you don’t remember to do this, all the sand is going to start draining right back out of the filter when you add it to the tank!

  • This is also a good time to check out the drain cap and this portion of your filter tank. If you notice any damage, cracks, or weakness, you may need to think about replacing the drain cap or finding a way to reinforce your filter in this area.

2. Use your garden hose to add some water back to your filter tank.

You should add enough water to fill about half the tank or just a little less. This will make it safer to pour the sand in without running the risk of damaging the laterals or cracking the filter tank, both of which are potential hazards if you dump a large amount of heavy sand inside the tank.

3. Gently put the laterals back inside the tank.

They won’t snap into anything, but they should fit snugly and securely into the bottom of the tank.

  • If you had to fold up the laterals to remove them, be sure they’re still folded up until you get them back inside the tank. Then just unfold them until the central pipe is securely in place.
  • Be sure your central pipe is still covered with tape or something else to keep sand from entering it.

4. Very carefully pour your sand or sand alternative into the filter tank.

sand

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This process may be very difficult if you’re handling a big, heavy bag of sand, and this is where a help may come in handy.

  • Be very careful to keep your central pipe and laterals in place while you’re pouring in the sand. Don’t let them move around so that they’re off-center when you’re finished. They need to remain in the middle of the tank.
  • If you have someone to help you, get them to hold the pipe in place while you pour to help make this part of the process go a little easier.

How to Close the Tank

1. Pick up your multiport valve and look at the o-ring on the bottom of the valve.

Most likely, you’ll want to go ahead and replace it with the new one at this time.

  • To do this, slip off the old o-ring and slip the new one on in its place. It belongs on the underside of the valve, below the lip that holds the valve in place.
  • You may need to add a little silicon lubricant to the o-ring to help get the new one on.

2. Take the duct tape off the top of the pipe and make sure it’s centered.

put the duct tape

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Line the bottom of the multiport valve up with the central pipe and gently slide the valve into place.

  • Don’t push down on the valve too hard, or you may risk breaking the central pipe.

3. Reattach the clamp you removed from the valve earlier using the screws you took off during the first part of this process.

  • You will probably need to use a screwdriver to complete this job. However, some filter models have clamps that can be reattached by hand.
  • Be careful not to over-tighten the clamps, or you might crack the plastic on the valve or on the filter.

4. Reattach the pipes or hoses to the pump and return ports on your multiport valve.

If you took the time to install unions earlier in this process, this will be new for you, but it is an easy process.

How to Check Your Filter’s Operations

1. Unroll your waste hose or line to the place where you’ll be dumping your waste water.

  • If at all possible, don’t dump your waste water out in your backyard directly into the ground. This is bad for the environment and could contaminate the drinking water in your home over time, too.

2. Turn the multiport valve to the backwash position.

Depending on your filter, you may need to push down on the valve before you can turn it, or you may just need to twist the handle to the correct position.

pool pump

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3. Prime your pool pump and turn it on.

If you shut off the breaker earlier, you’ll need to turn it back on before you can do this.

  • Open all of the discharge lines to your pump.

4. Allow your pool pump to run until you notice water coming out of the waste line fairly regularly.

From there, let it run for two minutes more to be sure it’s functioning properly and all the gunk inside your tank is flushed out completely.

turn on the pump

5. Turn off the pump once again and switch your multiport valve to rinse.

6. Turn the pump back on and let it run for about a minute.

You’re just waiting until the water you can see inside the tank is clear, so this shouldn’t take very long.

7. Turn the pump off once again and switch the multiport valve to filter.

8. Turn the pump back on. 

Your pool filter is ready to be used once again.

9. It’s a good idea to let your filter run at least one cycle before you use your swimming pool, just to be sure everything is operating correctly.

If you don’t do this, you can risk overloading the filter and causing it to work improperly or to spit sand back out into your swimming pool.

10. Before you leave your filter to do its job, take note of the pressure reading on your pressure gauge.

This is what a perfectly clean filter’s pressure should be. In the future, if you have trouble with your filter, you should remember this number so you’ll know what to aim for.

Conclusion

Now that you’ve learned all the steps you need to replace sand in pool filter tanks, you’re probably ready to run out to your backyard and get started working on your pool right away. That’s great! But don’t forget to take another look at the list of materials at the beginning of this article, too. Although some of them may not be required depending on the type of filter you have, you’ll want to have most of them on hand and readily available to help you take care of the job the right way the first time.

It always pays to have someone else to help lend a hand while you’re cleaning, too. It’s possible for you to complete this task on your own, but it will go a lot quicker and much easier if you have a helper who can hold tools for you and assist with pouring out large quantities of sand.

Remember, too, that if you ever feel like there’s a step in this process you can’t complete or there’s something that just isn’t clicking for you, that’s okay. Just call a pool technician to stop by and take care of the job for you. Some pool techs will be happy to show you how to perform these tasks on your own so you won’t have to worry about making an appointment the next time you need to replace pool filter sand.

With the information outlined above, you’re already well on your way to a better understanding of your pool filter. In no time, you’ll be able to change the sand and keep your pool as clean and sparkling as always without the need for any additional help.