Swimming Pool Sand: Where Does it Come From?


Swimming pools are convenient leisure’s devoid of the typical irritants you’d find at the beach like mass amounts of sand and algae-filled water. However, sometimes it seems a bit of the beach finds its way into your pool when you notice a mysterious layer of sand floating around your clean pool. Where is this sand coming from, and how can you prevent it?

Sand found in a swimming pool is typically caused by damaged components within its connected sand filter system. The most likely culprits are cracked laterals or a worn-out washer or O-ring at the top of the filtration between the standpipe and multi-port connection. To solve the issue, you’ll need to repair the broken components and remove the sand. 

Having gritty, irritating sand floating around your pool water and settling on the floor isn’t ideal, so we’re going to help you eliminate this issue. In this article, we’ll detail the most common causes for sand in your pool, as well as explaining how you can remedy and prevent these issues. 

Why Is There Sand in Our Swimming Pool?

Not all swimming pools experience this issue of mysterious sand floating around, but those that do almost always have something in common: a sand filtration system. 

The most common cause behind sand in a swimming pool is cracked laterals or worn-out components within its sand filtration system. These common pieces of equipment use natural sand to catch debris as it is pumped through your pool’s filtration system, resulting in clean pool water.

If these components are damaged or worn out, the filtration system cannot prevent the sand from seeping into the pool’s water. It will either pass the cracked laterals through the return jets or seep out between the standpipe and multi-port connection at the top of the filtration system. 

What are Sand Filters and How Do They Work?

Filtration systems are essential to a clean and healthy pool, as they remove mass amounts of debris and other contaminants from your swimming water. Sand filters are one of three popular pool filtration systems, and knowing how yours works can help you better understand why it is leaking sand into your swimming pool and what components might be damaged and causing this issue.

Sand filters are among the oldest and cheapest filtration systems you can equip your pool to ensure your water is clean and free of unnecessary debris. Essentially, water enters the filtration system and passes through the sand contained within. As it does this, the sand traps any debris within the water, and clean water then passes through the sand and out the filter back into the pool.

Inside each sand filter are a large amount of natural sand, a sand pipe, and laterals located at the bottom near the return jets. Because the standpipe and all laterals connected to the manifold are made of plastic, they can crack over time. This is why it is essential to practice proper sand filtration system maintenance to ensure all pieces are in optimal shape and functioning properly. 

How to Get Rid of Swimming Pool Sand

Knowing why there is sand in your swimming pool is only half the battle. Now you have to find a way to remove these pesky pebbles and ensure they don’t return. This ultimately requires two steps.

To remove sand from your swimming pool, you will first have to ascertain which component of your sand filtration system is damaged and causing the sand to leek into your pool water. You will then need to fix or replace this component. Once the filtration system is functioning properly, you can remove the sand from your pool using common pool cleaning tools. 

Sand filtration systems might be hefty pieces of equipment, but they’re relatively easy to fix when it comes to cracked laterals or worn-out washers and O-rings. Nevertheless, we’ll show you how you can easily fix these broken components and what pool tools to use to remove all of the sand floating in your pool water. 

Replacing or Repairing Sand Filtration Components

As we’ve said before, the most common reason behind your sand filtration system leaking sand into your pool water is cracked or burst laterals. These are the strong plastic components located at the bottom of your standpipe that have minuscule holes large enough to allow clean water through into the return jets but large enough to trap sand and keep it inside the filter. 

Luckily, replacing these components is fairly simple as long as you know how to maintain your sand filtration system. If you’ve changed your sand before, you will follow the same process but swap out the laterals before replacing your standpipe.

If you have never replaced the sand in your sand filtration system yourself, you can follow the guide listed below. We’ll show you how to perform this essential maintenance process and when to replace your laterals or any worn-out washer or O-rings if these are the cause of your sand leakage.  

How to Change the Sand in Your Sand Filtration System and Replace Damaged Components

After you’ve followed these simple steps, everything in your filtration system should be functioning properly, eliminating any sand leakage. 

  1. Acquire the materials below:
  • Pool filter sand
  • A screwdriver
  • A hose
  • A shop vac
  • Duct tape
  1. Remove the drain plug and drain all of the water out of the pool filter
  2. Remove the collar from the multi-port valve using a screwdriver and then manually unscrew the multi-port valve’s adjoining unions (note: not all systems have unions)
  3. Remove the multi-port valve by gently twisting and lifting it off from the system. 
  4. Cover the standpipe with duct tape to prevent any sand from entering inside the hollow pipe.
  5. Check your multi-port valve for any worn-out washers or O-rings. If you notice any, this is the time to replace them and solve your sand leakage issue.
  6. Turn on your shop vac and use the hose to suck all sand out of your sand filtration system.
  7. Lift the standpipe and check your laterals without removing them. If the laterals are broken, remove the standpipe and replace the laterals now. If they are not, it is easier to proceed with the laterals still inside the filtration system. There is a chance it is your standpipe that has cracked, so check this as well in case it needs replacement.
  8. Use a hose to rinse the inside of the filtrations system, including the standpipe and laterals, to remove any remaining sand. 
  9. Replace the drain plug and fill the filtration system halfway with water ensuring the standpipe stays centered inside the tank.
  10. Fill your filter with the necessary amount of sand (this will depend on your filter size)
  11. Remove duct tape covering the standpipe and replace the multi-port valve (this is your last chance to check the washers and O-rings for replacement). You can use some lubricant to get the valve in place more easily. 
  12. Replace your multi-port valve unions and collar.
  13. Attach the filtration system’s backwash hose and backwash the system for about two minutes.
  14. Set your filtration system to “rinse” mode and rinse it for one minute.
  15. Set your filtration system to “filter” and ensure everything is functioning properly. 

Once you are sure everything is running as it should, not only will your filtration system have new, coarse sand, but your sand leakage problem should also be solved. 

Removing the Sand That Already Leaked into Your Pool Water

When it comes to sand leaking into your pool, you always want to prioritize solving the root of the issue and replacing any broken components. Of course, the next step is to get rid of all the sand floating around in your pool water or settling near your filter system. 

True, a fixed sand filtration system should be able to draw all of that sand back in and filter it out, but this could take a long time, depending on how much sand has seeped into your pool. For instance, if your laterals have burst, you might have piles of sand sitting on your pool floor.

The best way to remove this sand is to use a pool brush to carefully brush all of the sand into one or multiple manageable piles. Try to be as gentle as possible with this process so you don’t cause mass amounts of sand to disperse into your water.

Once your sand is swept up, use a pool vacuum to suck up the piles of sand, again minimizing how much you disturb the piles. You can then test and balance your pool water to ensure the water is at the proper levels after you’ve cleaned and repaired everything. 

How to Prevent Swimming Pool Sand from Getting in the Pool

Your pool is now sparkling clean, and all of the sand is where it should be. But how can you make sure it stays there, and you don’t have a repeat of this issue?

The best way to guarantee sand doesn’t leak into your pool through your sand filtration system is to conduct regular maintenance on this system while it is in use and ensure it is in the proper mode or shut down and stored during freezing temperatures. 

Routine maintenance is what will give you peace of mind that all of your sand filtration system’s components are in optimal condition and functioning properly. 

As a whole, your sand filtration system should last you about 15-25 years, and as long as you backwash and rinse the system routinely in addition to necessary sand changes, you should have no problems with sand leakage. 

The sand in your sand filtration system will typically last about 5-7 years, but most pool owners will change it every three years or so when the coarseness of the sand diminishes and reduces effective filtration. Every time you change your sand, check your standpipe, laterals, washers, and O-rings to ensure they don’t need replacement. 

Because these components are also made from plastic, you’ll want to ensure your filtration system is functioning or stored properly during freezing temperatures. If these temperatures are uncommon in your region, set your valve to “winterize” on the rare occasion, it occurs to the water continues to flow and doesn’t freeze. 

If below freezing temperatures are common in your region, you’re better off emptying your filtration system, closing your pool for the season, and storing it somewhere warm and dry. This will ensure the components don’t crack from water freezing and thawing around them. 

What If I Find Sand in My Pool and I Don’t Have a Sand Filtration System?

If you find something that appears to be sand in your pool but you don’t have a sand filtration system, you might have a more serious issue on your hands.

If you find a sand-like substance in your pool, but you don’t live near a source of sand or have a sand filtration system, it is most likely from yellow or mustard algae. Although rare, this persistent organism is typically found in southern climates and can attract harmful bacteria like e. coli.

The bacteria itself is not harmful to humans, but it can attach to objects within your pool, such as floaties, swimsuits, and pool toys that can be transferred onto other objects in your home. 

To determine if the sand-like substance in your pool is mustard algae, take a pool brush and lightly brush the substance. If it disperses into a cloud rather than a sandy clump, it’s most likely mustard algae. 

How to Get Rid of Mustard Algae

The best way to remove this annoying menace from your pool is through chemical treatments. Because it is chlorine-resistant, you’ll need to get a little creative with your treatments. First, clean all of your bathing suits and pool tools or elements using bleach to kill any mustard algae that might be on these objects. This will ensure you don’t reintroduce the algae to your pool after removing it.

You can then use an algae brush or a vinyl pool brush to scrape the algae off surfaces and into suspension. Next, don some chemical safety gear like gloves and goggles and wait until the sun goes down before you add 3 pounds of calcium hypochlorite shock for every 10,000 pounds of water in your pool. 

Afterward, keep your cholerine high while keeping your pH and alkalinity balanced and constantly brushing off any mustard algae from your pool surfaces until the issue has been eliminated. 

Final Thoughts 

Now that you know the main causes behind your pool’s sand issue, you can solve the issue with ease and ensure it doesn’t return to ruin your watery relaxation. If you don’t have a sand filtration system for your pool, test your water to see if the root cause of your issue is mustard algae and not sand. 

Sand might be irritating, but mustard algae can stick to various surfaces and carry harmful bacteria, so it should be removed from your pool and pool objects as quickly as possible. If at any point you need help removing either of these contaminants from your pool, contact a professional pool cleaning service for assistance.

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