Before we get into our step by step guide on how to change the sand in a pool filter, you should know that if you have a pool, it is really important that you keep on top of cleaning and maintenance, as these are two things that can easily get out of hand when left unattended.
One of the most important things to keep an eye on is the pool filter, as this is an essential piece of equipment for pool cleaning.
Any and every pool filter will need to be cleaned and the if you have a common pool sand filter, the sand inside will need to be changed every now and then. If it is time for you to do this, you might be left wondering what you are supposed to do…
To help you to understand how to change the sand in the pool filter, we are going to tell you everything that you need to know in this article.
We will provide you with a step-by-step guide on how to change the sand in your pool filter to make the experience easier.
Table of Contents
How to Properly Change Pool Filter Sand
If you need to change the sand in your pool filter, the first thing that you need to do is open the filter.
Inground Swimming Pool Filters that have the multiport valve mounted on top of them will usually require you to disconnect the plumbing that runs to the valve. We will explain more on opening your filter below.
If you do not have unisions on the pipes, you will need to cut them in order to remove the multiport valve.
You might also want to consider installing unions on these lines to facilitate future service on your filter, but this is totally up to you. Depending on what type of sand filter you have, accessing and replacing the sand may vary. See our guide for each filter type below.
Side Multiport Valve Filters
Filters that have the multiport valve mounted on the side will have either a small top that can be removed, or a tank that is bolted or clamped in the middle, which can be taken apart.
If your filter is a two-piece tank that is bolted or clamped in the middle, you should pull the drain plug first to allow for the water to drain before you pull the tank apart.
Once you have done so, it is quite easy to remove the sand.
Single Piece Filter WIth Top Opening
If your filter is not the two-piece type, but it still has a small opening at the top from either a multiport valve or cover, there are two methods that you can follow to remove the sand.
The first of these methods involves a filter that has a plug at the bottom and allows the sand to flow out. This is usually a larger plug that will be threaded to your winterizing drain plug.
Once you remove this plug, you can use your garden hose to wash out the sand from the tank.
Single Piece Filter Without Drain Plug
If you have a single piece tank that does not have this type of drain plug, then you will need to dig out the sand through the top with a cup.
The first thing you need to do is pull the drain plug to get rid of the water. If there is a top-mounted multiport valve, there will be a stand pipe in the middle of the opening.
Do not try to move this out of the way, as it can cause damage. You will need to dig out the sand with a small cup.
Once you have managed to get rid of enough sand to expose the laterals, you will be able to move the stand pipe out of the way.
If the valve is side-mounted, you will have an overdrain that will fill the opening at the top. This can be removed, usually by unscrewing it.
You will then be able to rotate the pipe that it is connected to by moving it to the side.
Sometimes, the overdrain will be glued to its pipe, which means that you will have to rotate the pipe with overdrain out of the way. You will then be able to dig out the rest of the sand.
Be Gentle With Your Pool Filter Laterals
You will need to be really careful when you are digging out the sand, as you could otherwise cause damage to the laterals in your filter.
These are very fragile, which is why it is important to take your time and be gentle. This is also the main reason why you shouldn’t use a shovel. Once all of the sand has been removed, you should clean and examine the laterals.
The majority of laterals will unscrew, which makes them really easy to remove from the tank for cleaning. If you have a two-piece tank, then the laterals could snap in instead of being screwed.
If this is the case, you should be able to remove the entire underdrain assembly in one piece.
If they are glued in, you will not be able to pull them off. Make sure to check for any signs of damage. If anything is broken, it will need to be replaced immediately.
Properly Cleaning Pool Filter Laterals
To clean the pool filter laterals, you can soak them in a mixture of muriatic acid and water, especially if there is a lot of dirt on them.
You will also need to thoroughly rinse them afterwards. Once you have done this, you can rinse out the tank and reinstall the clean laterals.
Replacing the Swimming Pool Filter Sand
Once you have followed all of the above steps, you will be ready to replace the sand. You should replace the underdrain assembly, then add water until the tank is half-full to protect the laterals when you add the sand.
After you pour in a bag of sand, level it out before you add the next one. Fill it with sand to the level that is indicated by the manufacturer.
Once the right amount of sand is added, you will need to reassemble the filter tank and/or multiport valve.
You will need to start the system in backwash mode, as this will flush out all of the dust from the sand and allow the sand to completely settle.
For video instructions, check out the step-by-step video by BuildersSA below! Also, we recommend you see our full guide on How To Fully Clean A Sand Pool Filter as well, which goes much more into the cleaning details.
My name is Denise and I am an Analytical Chemist located in the Kansas City metro area. Some things I am passionate about are gardening, science, swimming, and blogging. I am happy to be part of the All About Pools team & contribute my knowledge & expertise to help swimming pool owners and backyard enthusiasts!