How to change sand in your pool filter. We already know that water filtration is an important step in the physical treatment of the pool. In the pool filtration system, one of the most vital components is the filter. And just like a typical motorcar runs on gasoline, your pool filter runs on sand. When the overall filtration system or the sand is excessively dirty or not maintained, you stand the risk of having a milky, whitish or cloudy pool with an opaque appearance.
A lot of people ignore it and a lot of people change the filter sand and do not even know why!
Initially, we will talk about various points such as how to know it’s time to replace the sand, the filter sand saturation process. Finally, we will show you how to replace sand in pool water, while giving you tips on handling the task.
How does a pool sand filter work?
Basically, the function of the pool filter sand involves retaining the particles that pass through it. This way, it ensures the water returns clean to the pool. Meanwhile, over time, the accumulation of these particles hinders the process of filtration and backwashing. Hence, it becomes necessary to replace the pool filter sand.
The sand for pool filtration has edges that hold dirt when water passes through them. The problem is that with the passage of time, the sand of the filter is getting worn out with the whole process and with the backwash. So the edges are often polished by the water, causing the grains of sand to become increasingly rounded, with filtration of water returning to the pool.
Why do pool filter sand replacement?
What happens is that during filtration of the pool, the suspended material passes through the filter, and the small sand granules retain the particles so that the water returns to the clean pool.
Over time, the material retained in the sand decreases the flow of water inside the filter. The sand of the pool filter undergoes wear, undergoes polishing, and the grains become smaller. Anyway, the sand hardens and gets dirty. Compressed, it loses its properties to perform a good quality filtration.
Consequently, this increases the filtration time, as the return flow decreases dramatically.
The friction caused between the sand granules during the filtration process causes them to wear out, and the dirt holding capacity decreases.
It is interesting then to do an annual review on the filter to see if there is a need for sand replacement or replacement.
In pool water, there are generally high concentrations of magnesium and calcium ions, which stick to the sand and form blocks (silicates). Passing through the filter, the pool water finds the silicates in its path. Since it can not cross them, it deviates from them and will not go through.
One way to avoid this problem is to control the pool filter sand quality by checking for silicate blocks and maintaining the correct pH levels.
To eliminate sand-trapped materials, it is necessary to perform a backwash of the filter, according to the instructions of the filter manufacturer.
Basically, the maintenance of the filter consists of 2 operations: cleaning and backwashing. If this backwash is not regularly performed, the chances of the sand presenting problems will increase. Do the cleaning at least once a week when the pool is in use. However, in winter, do it once a month. In highly limestone waters, we recommend annual chemical cleaning. For example, the descaling of the sand.
When to replace the sand of the pool filter?
Changing the sand from the pool filter happens on two occasions:
- When sand is missing from the filter.
- When you notice the sand of the filter saturated with debris.
When does the filter run out of sand?
The sand of the filter usually does not diminish considerably when it is operating inside the filter. Although, some sand may be lost whenever backwashing is done.
However, yes, it may happen! The sand level inside the filter may decrease due to some filter problems.
Basically, the most common problem that leads to sand loss is when there is a defect in a part of the filter. For example, when the standpipe or one of the laterals break.
In this case, the filter loses some of the filtration capacity and gradually loses its sand.
It is easy to see when the standpipe or one of the laterals of the filter breaks down during filter operation. It throws sand into the pool through the return nozzles.
Usually, you only notice the sand when it stops at the bottom of the pool.
When does the filter sand become saturated?
We say that the filter sand gets saturated when it is so dirty that it loses its filtration capacity. Basically, some factors which accelerate the filter sand saturation process are:
- Use of aluminum sulfate: Suctioning the pool by filtration after using aluminum sulfate as a decanter is extremely damaging to the sand of the filter. This is because it joins the grains of sand by grinding it. So, all of that sand actually turns into a bunch of gravel. And we know that the bigger the grains of sand, the more dirt that will return to the pool even through the filter.
- Sucking a lot of dirt: This will leave you surprised as, after all, this is basically the filter’s purpose. However, when the pool is too dirty, it is important to check the possibility of sucking the dirt to the sewer so that all that dirt does not pass through the sand of the filter. Sometimes vacuuming the pool by filtering is very damaging to the sand of the filter.
- Lack of backwash: It is interesting to backwash and rinses the pool filter sand whenever the filtration is not already 100%! Even after backwashing and rinsing, the filtration is still not efficient, it is probably time to change the filter sand.
How often should you change the sand in a pool filter?
In general, experts recommend that you replace the pool filter sand after 3 to 5 years of water use. Meanwhile, if the water does not contain too much limestone and the filter is always well maintained, this period may extend up to 7 years.
However, you should avoid the frequent exchange of the sand without the filter presenting any problem.
You may consider replacing after 2 or 3 years to keep the filter sand at the proper level. For this operation, you must use sand with the same granulometry. That is, the dimensions of the grains must be equal.
How much does it cost to change sand in a pool filter?
The cost to replace sand in pool filter is relatively low. If there are no damages to the filter, you should be looking at a maximum of $200. On average, a 50lbs 20# grade of silica sand costs just $30.
If you follow the steps provided in this article how to change sand in your pool filter, you would be saving the cost of an expert. However, if you are to call in a pool company for the replacement, you have to budget around $100 as labor cost.
How much sand goes in a pool filter?
Can you put too much sand in a pool filter? Of course, yes. Too much sand in the filter may make rinse cycle and backwashing less effective. The best practice is to leave at least 6 inches of space between the top of the filter tank and the level of the sand.
What kind of sand do you use in a pool filter?
Play sand or masonry sand would not work in your pool filter. Instead, you have to choose a high-quality grade #20 silica sand, zeolite or glass sand with each grain measuring between 45 to 55 mm. This is because the features of this type of sand help trap small particles which measure as low as 20 microns.
Tests to know if it is time to change the sand of the pool filter
Actuality, there are some simple tests one can do to make sure the time has come for the replacement.
- First, check that the flow rate on the injectors is weaker after filter cleaning.
- If it is, observe the transparent filter hood and see if deposits of limestone appear.
- If you confirm the presence of these deposits, then, it is infallible evidence that you need to change the sand of the pool filter.
Meanwhile, you can still see if pool water, although chemically balanced and filtered periodically, is not in good condition.
- Another thing that you can do is to open the filter and dip your hand into the sand.
- If the sand flows between your fingers, you do not have to change it yet. However, if the sand has hard blocks, then, you need to replace it.
- If you notice that the sand is disappearing from inside the filter and identify signs of it in the water, you will need to remove all the sand to fix the equipment. This is a problem in the laterals, which you can find at the bottom of the filter.
Finally, have you done these tests to make sure the time has come to change the pool filter sand? The next task ahead of you is to finally replace the sand.
How do I change the sand in my pool?
So, let’s start right away, starting from everything you need to do this delicate operation:
- Screwdriver (electric or manual)
- Sand for the filter (quantity to be checked based on the type of filter)
- Strong adhesive tape (insulating tape better)
- Ash vacuum cleaner
Step 1. Turn off the pool filter and allow the water to drain
First off, turn off the pump and the filter and make sure the timer is not set to ON. If the pump runs dry, it may burn out! You must then remove the drain plug from the bottom of the filter tank and allow all the water to drain out. This may take a while, so you shouldn’t be in a particular hurry.
Step 2. Remove the selector valve
Nex, you have to remove the tubes that connected to the selector valve. If the valve is firmly sealed to the PVC pipe, you will need to cut the pipe and install the suitable pipe union, so that you can change the sand more easily from here on out.
Next, remove the clamp or collar that connects the valve to the tank. You may need the screwdriver for this task.
Once you remove and disconnect the collar and tubes, pull the selector valve to remove it.
Note: Since the valve connects to a hydrant that passes through the sand of the filter, in the lower part of the tube there are lateral star-shaped tubes with micro-perforations that allow only the passage of purified water and not sand. Therefore, it is better not to twist or bend with too much force. This is because the sides could break under the weight of the sand.
Step 3: Cover the hydrant
Inside the tank, you will see the pipe that descends into a large pile of dirty and old sand. Before removing and adding new sand, you must cover the upper part of the hydrant with adhesive tape.
You don’t want the sand to end up in the pipe, do you? In fact, when the change of sand is finally finished and you switch the filter on again, there is a risk that the sand will end up in your pool.
Step 4: Remove the sand
Would you like to know how to empty sand filter? It’s simple enough. Remove all the sand using the dust or ash vacuum cleaner or a large vase and dig manually.
Step 5: Rinse the tank and the side tubes
Now, it will be even clearer how lateral tubes emerge from the main hydrant. At this point, you can use a garden pump to rinse the rest of the filter sand.
However, you should take advantage of this operation to check that all pipes are free of cracks or other damages. If otherwise, in fact, you need to replace them immediately before adding the new sand. You don’t want to ask why is their sand in my swimming pool immediately after replacing the sand.
Step 6: Fill the tank halfway with water
Before adding the new sand into the filter, replace the drain plug on the tank. After this, half-fill the tank with water.
This will cushion the fall of sand on the micro-perforated side tubes, protecting them from breakages.
Step 7: Add the new sand
Generally, sandbags are very heavy. So we recommend placing one bag at a time in an upright position on the top of the tank and cutting the bag, letting the sand slowly pour into the filter.
However, depending on the size of your filter tank, you may need to do this several times. Remember: take all the time necessary to prevent the sand from escaping everywhere. And make sure the tube is always covered.
Warning: Use only the filter sand suggested by the dealer!
Step 8: Fill all the water tank
When all the sand is in the filter, fill the rest of the filter with water. Replace the selector valve, collar, and tubes securely and securely.
Step 9: Backwash and rinse the filter
Before you turn on your filter and pump, set the selector valve on the entry Backwash. Turn on the filter and let it rinse for at least 2 minutes or until the light signals the execution of the operation. This will help to drain all the impurities that have accumulated inside the tank.
Then turn off the pump, set the selector valve to Rinse, turn it back on and rinse the filter for about 1 minute.
Step 10: Re-activate the sand filter
Perfect! The change of sand happened correctly (or at least we hope so). Next, you just need to switch off the pump, set the valve to Filter and restart the pump.
Lastly, you have to check the pressure gauge. What should be the normal pressure in the filter changes from manufacturer to manufacturer?
But, generally, the correct value is between 0.5 and 1.5 Bar and between 0 and 4 PSI for the American measures. Always keep an eye on this factor. Meanwhile, when the pressure value exceeds the normal value, it is necessary to backwash the filter again. In this way, you can eliminate even more debris; little ones!
Tips to extend the sand life of your pool filter
Here are some tips for an effective pool sand filter maintenance:
- Always clean the pool pump pre-filter after the suction to remove leaves and other retained dirt. This helps you avoid clogging and therefore facilitating the filtration process.
- Always clean the skimmer basket.
- Clean the edges of the pool to remove excess dirt. You can use a sponge of your own.
- Brush and sift the pool. Basically, this helps to remove dirt and possible stains from the pool walls. Also, it helps to remove solid materials from both the surface and the bottom.
- By observing these tips you prolong the good dirt retention capacity of your filter. But it is always good to remember: it is essential to carry out changing the filter sand of the swimming pool with a minimum frequency of every two years!
You may check out more tips and tricks below:
We hope you enjoyed the article. Use the comment box below if you have questions or would like to make contributions.
Table of Contents
- 1 How does a pool sand filter work?
- 2 Why do pool filter sand replacement?
- 3 When to replace the sand of the pool filter?
- 4 When does the filter run out of sand?
- 5 When does the filter sand become saturated?
- 6 How often should you change the sand in a pool filter?
- 7 How much does it cost to change sand in a pool filter?
- 8 How much sand goes in a pool filter?
- 9 How do I change the sand in my pool?
- 9.1 Step 1. Turn off the pool filter and allow the water to drain
- 9.2 Step 2. Remove the selector valve
- 9.3 Step 3: Cover the hydrant
- 9.4 Step 4: Remove the sand
- 9.5 Step 5: Rinse the tank and the side tubes
- 9.6 Step 6: Fill the tank halfway with water
- 9.7 Step 7: Add the new sand
- 9.8 Step 8: Fill all the water tank
- 9.9 Step 9: Backwash and rinse the filter
- 9.10 Step 10: Re-activate the sand filter
- 10 Tips to extend the sand life of your pool filter