A sand filter is one of the best pool filters you can use. It offers an excellent way to keep your swimming pool free of contaminants by trapping them in the sand. And you know what, a sand filter is the huge tank-like unit next to the pool pump if you didn’t know. It requires low maintenance; all you need is to backwash it to remove the sand’s contaminants to avoid saturation. But after years of filtering, the sand will require renewal.
I think you’re there, and that might be the reason you’re searching for how to change pool filter sand. This post is here to give you an insight on what’s a sand filter, its purpose, why you need to change it, and how to change it. Read on to know more.
What is the purpose of pool filter sand in a sand pool filter?
I understand you want to know how to change pool filter sand, right? But what is a sand pool filter? You might be using it with your above or ground pool, but do you know what it is?
A pool filter is an essential piece of equipment in pool maintenance. Its primary purpose is to pull dirt from the pool water.
And sand filter, one of the three types of pool filters used for pool filtration, uses the sand to trap the water contaminants before returning to the pool. Filter sand is available in various varieties, which I will discuss later.
The sand is the filter media, the stuff that grabs the contaminants. It’s an excellent filtration media requiring low maintenance and exceptionally durable.
It traps the dead bugs, algae, bacteria, and the small debris that the skimmer net can’t catch. It helps prevent these contaminants from causing cloudy water or getting you sick.
That might be the reason it’s also used in wastewater treatment, drinking water, and septic systems.
Like the small-particle sand found on the beach, Filter sand has a rough surface that catches the contaminants as the water flows through it.
And as you can imagine, the number of particles in a bag of sand is enormous. So, it’s a lot of rough surfaces the contaminants have to go through. That’s why it’s so effective.
How often should you change pool filter sand?
Even though the sand filter is exceptionally durable and low maintenance, you will need to change the pool filter sand at some point.
According to pool experts, filter sand needs to be changed after every 3-5 years, mostly 5-years, depending on pool sand filter usage.
Why change pool filter sand
Over the initial years, the filter sand is quite effective. The contaminants trapping is effective, and as they build up inside it, they make the filter more efficient.
During the first couple of years, the build-up improves the filterability to trap more contaminants pass through it.
Eventually, the gunk builds up so much that it clogs the filter. When this happens, the pressure starts to build up, causing leaks and forcing the water to seek an alternative path with low resistance.
That is why you do backwashing. But after the extended water filtration and backwashing, the sand loses its effectiveness. The efficiency of trapping the contaminants reduce due to the withered surfaces.
The rough surfaces become smoother and fail to catch the tiny debris, algae, and dust, allowing them to make their way back to the pool.
How can I tell it is time to change pool filter sand?
You will always get clear signs when your filter sand needs changing. A series of signs come up when the sand gets saturated.
One of the signs to tell you your sand finder requires new sand is when pool cleaning becomes more tedious than before.
When your pool starts losing its sparkle, becoming dull, that is an indicator there is tiny debris getting back to the pool.
If you start seeing sand particles in your pool floor, that is another sign your pool filter sand is exhausted.
What happens when the sand particles smoothen is reduced in size, and start to pass through to the return lines. When water passes through, they are forced out and end up in your pool water.
Another sign is when you start doing more backwash and rinse cycles than you did before to get the sand clearer.
If your pool sanitizes still effective and the sand filter isn’t, then there is a chance your pool water will get cloudy.
When you get a cloudy pool and foamy water when the sanitizer and other chemicals are balanced, you filter sand requires changing.
The bacteria and algae killed by the Chlorine won’t be trapped in the sand, meaning they will end up back in the pool water.
What types of pool filter sand are available?
Pool sand filters use three types of sands; silica, glass, and zeolite sand. To the untrained eye, these filter sands look the same.
Most people assume the sand is made equal, but no. You cannot use the cheap play sand you come across. It’d damage your pool filtration system.
You must check with your sand filter manufacturer the recommended sand type. The following are the most common three.
#a) Silica Sand
Silica sand is a mined sand – not manufactured. #20 silica sand is the most commonly used variety; it’s processed from ground quartz.
The quartz creates sharp silica grains with rough edges, making it excellent for trapping the pool water contaminants.
#b) Glass Sand
As the name suggests, glass sand comes from recycled glass. It’s smoother to the touch, but it works quite well in capturing the smallest particles.
It’s also the perfect option for those looking for an effective filter media than silica and friendly to the environment.
The grass grains in glass sand are of different sizes. That minimizes channeling when the pool water passes through the media in a straight path going virtually unfiltered.
Also, glass sand is negatively charged; it works excellently at capturing the manganese and iron particles. It’s something you want to consider if you fill your pool with a hard water source.
#c) Zeolite Sand
Zeolite sand comes from volcanic rock minerals, the zeolites. It boasts a greater surface area than the standard water filter sand thanks to its sponge-like shape.
It excels in trapping chloramines, a by-product produced by the sanitizer and which causes red eyes in swimmers. It does this chemically through the molecular sieving process.
Zeolite sand helps control chloramines with low pool chemical additives, especially during repeated pool shocking.
How to Change Pool Filter Sand (Step-By-Step Guide)
Now that you know what it entails when we talk of pool filter sand let us jump to the order of the day, guiding you on how to change pool filter sand step by step.
Step 1: Gather your Materials and Equipment
- 2 – 4 bags of Pool filter sand (check your filter’s manual for the amount)
- Shop-Vac or Sand Extractor Pump
- Duct tape or Rubber plug & Screwdriver
- Garden hose
- Filter Backwash hose
- Diatomaceous earth (D.E.) powder (optional)
- Filter O-ring Replacement
- Movable Garden Cart or Wheelbarrow cart
Step 2: Backwash the Filter
Backwashing the filter loosens the sand particles making it easy for you to extract. It does also remove all the sticky gunk that might have accumulated inside there. Backwashing makes the extraction relatively easier.
Turn off the pump partially. Set the multiport valve to backwash and connect the backwash hose and run the pump to ensure everything drains out and you’re left with clean loose sand.
Step 3: Turn Off the Pool Pump
The next thing you need to do is to stop the water flow to the filter. That’s why you need to turn off the pool pump and the filter.
Also, ensure the pool timer isn’t on as it could start the pool pump, and it were to run dry, it could cause it to burn out.
Step 4: Open & Remove the Cover or the Multiport Valve
Not all sand filters are the same. Some come with the multiport valve on top, while others have it on the side.
If your sand filter has the multiport valve on top, you will have to remove it. The first thing you need to do is disconnect the pipes running to the multiport.
If they are a hard plumber with the PVC pipe, it’d be best to cut the line. If you’re not comfortable with the task, you can hire a professional for the job.
After cutting the pipes, install union fittings to make it easier to remove them during the next maintenance.
Using a screwdriver, remove the screws, clamp, or collar that secures the valve to the tank. Twist the unit gently and remove it.
Note: the pipe connected to the valve that runs through the sand has laterals or fingers. Rushing things or hard-twisting could break them. So take it slow.
If your pool sand filter uses a separate multiport valve, you will need to unscrew the top cover using your screwdriver.
Step 5: Cover the Outlet Pipe and Breather
Once you open the filter tank, there is an outlet pipe and breather on the inside. You must cover them up with duct tape or a plastic bag and a rubber. That will prevent sand from going down the pipes. If the sand gets through, it’ll be flushed by the incoming water right inside your swimming pool.
Step 6: Remove the Sand
It’s time to get your hands dirty. You can use a filter sand extractor or a Shop-Vac to extract the sand out.
Find an ideal place to extract the sand to like a Movable Garden Cart or Wheelbarrow cart, for more straightforward disposal.
While removing the sand, remember to gently not damage the filter fingers on the filter tank bottom.
Step 7: Rinse the Filter Tank and Laterals
Now that all the sand is gone, you should be able to see the standpipe and the filter finger at the bottom.
Take your garden hose and use it to rinse the sand that is remaining in the tank. You could use the shop vac to suck it out or leave it to drain through the drain hole.
Before you can move to the next step, inspect the outlet pipe and the filter fingers/laterals for damage. Please make sure there no cracks as they could allow the sand to slip through into your pool.
Step 8: Refill the Filter Tank Halfway with Water
The laterals are delicate and adding the water before the sand offers a protective layer to protect them from the falling sand weight.
Replace the drain plug and use the garden hose to fill the filter tank. Ensure the outlet pipe, laterals, and the breather are in the proper position, the center. You could hold them in place until the tank fills halfway.
Step 9: Add the New Sand
With your safety mask on, you can start pouring the sand into the sand filter. Remember to check the coverage on the outlet pipe and the breather to ensure they are sealed well.
The best way to pour the sand inside the tank is to hold the sandbag with the corner while extending it over the tank opening.
Slice it with a utility knife and allow the sand to pour slowly inside the tank. Remember to add one bag at a time.
It’s at this time that you can add a few cups of Diatomaceous earth (D.E.) powders along with the sand. It helps in boosting the sand filter filtering efficiency.
Remember to put the sand to around 70% of the tank, do no fill the tank to the top to give the water some room before getting filtered.
Step 10: Fill the Tank with Water
Use the garden hose to fill the tank with water. Don’t mind the color of the water. It’s from the newly added sand and should clear out during backwash.
Step 11: Reassemble the Connections
Once you’ve replaced the sand and filled the tank with water to the top, it’s time to cover things up.
If you removed the multiport valve, collar, and other pipes, reassemble everything the way it was previously. Ensure everything fits snugly and secure.
If you unscrewed a filter cover, use the new O-Ring replacement to replace the old one, take the screwdriver and screw the filter cover back on, tight and secure.
Step 12: Backwash and Rinse the Sand Filter
Once everything is attached, it’s time to get things cleaned.
First, you have to prime the pump and then turn it on.
Set the multiport valve to backwash setting and then open the drain valve for two minutes or until the water in the tank clears and you can see the sand.
Backwashing helps remove the sand dust and other debris from the newly added sand.
Next is to rinse the filter. Turn off the pump, set the filter to rinse setting, and turn on the pump. Allow the filter to rinse for a minute.
Step 13: Run the Filter
Shut off the pump again and set the pool filter to the filter setting. During this time, check the pressure gauge to make sure everything is running normally.
Check your sand filter manual to know what regular pressure reading should be. If it’s above average, the filter sand will need more backwashing. Repeat the backwash steps and recheck the pressure readings.
As you can see, how to change pool filters sand a simple process. The hard part is choosing the type of sand and maybe cutting the pipes when disassembling the multiport valve. Other than these two, the whole thing is a walk in the park.