We’ve been quite busy with recent posts to help you out with some home pool maintenance tips, and this blog is no exception.

Today, we’re diving into the world of sand filters and demystifying the art of backwashing.

Don’t worry, we’ll keep it as simple as possible with easy-to-follow steps. So, grab your sunscreen and let’s get into the refreshing waters of sand filter maintenance.

What Is a Sand Filter?

First things first, let’s get acquainted with your pool’s very important element – the sand filter.

Less of a plot twist here, a pool sand filter uses sand to filter pool water. The water passes through a chamber filled with sand, trapping particles, debris, and other contaminants. The purified water flows out of the sand filter and back into the pool.

sand filter

A pool sand filter uses silica, quartz, or garnet. These natural materials are proven to trap dirt and debris from water. They also help to improve water clarity and reduce chemical usage in pools.

Just imagine it as your pool’s spa day, your sand filter is a place where all the gunk and debris from your pool water come to take a timeout. As pool water flows through the sand, the tiny particles get trapped, leaving you with clean, sparkling water on the other side.

Think of it as your pool’s personal cleaning crew, working tirelessly to keep your water looking its best.

How Does a Sand Filter Work?

Now, let’s peek under the cover and understand how this all happens. Your sand filter is like a water purification expert, going through the same process again and again. Here’s how it works:

1. Filtration

When pool water enters the filter, it flows through the sand bed. The sand acts as a natural filter, capturing impurities, debris, and even microscopic particles, leaving only pure, clear water to continue its journey.

2. Pressure Builds

As the sand bed collects more and more particles, it becomes less permeable, causing water pressure to increase within the filter. This is where backwashing comes into play (more on that in a bit).

3. Rinse and Repeat

Your sand filter keeps working its magic, cycle after cycle. Eventually, when the pressure reaches a certain point, it’s time to give the sand a break with a backwash.

Why Use a Sand Filter?

Good question.

First let’s look at the difference between

  • Sand filter,
  • Diatomaceous Earth (D.E.) and
  • Cartridges

when it comes to filtering capabilities.

D.E. removes particles down to three microns, all the time. A micron is very small – a millionth of a meter.

Cartridge filters work down to 40 microns only when they are working correctly.

Sand filters work around 100 microns right after they are backwashed, and get down to about 75 microns when they are dirty.

Now, we’ve got some pretty compelling reasons for you to choose a sand filter for your swimming pool.

1. Simple yet Effective Filtration

A sand filter is a very simple apparatus – it’s basically an empty bucket filled with sand. As water passes down through the sand, dirt is caught in the spaces between the pieces of sand. When the sand is full of dirt, you flush it out.

2. Low Maintenance

Compared to some other types of pool filters, sand filters are relatively low-maintenance. With proper care, they can last for many pool seasons.

3. Economical

Sand is a cost-effective filter medium, and replacing it is a straightforward process when the time comes.

4. Easy to Operate

Sand filters are user-friendly and don’t require constant monitoring or adjustment. Just let them do their thing.

How to Backwash a Sand Filter

Ah, now comes the fun part – backwashing! It’s like giving your sand filter a spa day of its own. Here’s a step-by-step guide on how to backwash your sand filter.

Step 1: Turn Off the Pool Pump

Safety first. Always start by turning off the pool pump to avoid any accidents.

Step 2: Set the Valve to “Backwash”

Locate the multiport valve on your sand filter, and turn it to the “Backwash” position. This diverts the flow of water, so it flushes out the trapped debris in the filter.

Step 3: Turn On the Pool Pump

Now, turn the pool pump back on and let it run for a few minutes or until the water in the sight glass (if your filter has one) runs clear. You’ll notice the water exiting the filter is cloudy and discolored at first – that’s the dirt and debris making their grand exit.

Step 4: Rinse

After the backwash, turn the pump off and turn the valve to the “Rinse” position. Now run the pump again for about 30 seconds. This rinses the sand bed and ensures any remaining debris is expelled from the system. When finished, turn the pump off.

Step 5: Return to “Filter” Mode

Once you’ve completed the backwash and rinse, turn the valve back to the “Filter” position. Now you can turn the pump on again.

Step 6: Check and Adjust

Keep an eye on your pool’s water pressure gauge. If it starts to rise significantly, it might be time for another backwash.

Of course, the steps may slightly differ depending on the type of sand filter pump you have. Check out the video below from our very own Marcus to go through the steps again of how to backwash your sand filter.

How to Replace a Sand Filter

While sand filters are known for their durability, there will come a time when it’s necessary to replace the sand bed. Here’s how you can do it.

Step 1: Turn Off the Pool Pump

As always, begin by turning off the pool pump to ensure safety.

Step 2: Release Pressure

Open the air relief valve to release any pressure inside the filter tank.

Step 3: Remove the Old Sand

Carefully remove the tank’s lid and scoop out the old sand using a plastic scoop or your hand. Be sure to dispose of the old sand properly, following council regulations.

Step 4: Inspect the Laterals

Take a look at the laterals at the bottom of the filter tank. If you notice any damage or signs of wear, this is a good time to replace them as well.

Step 5: Add New Sand

Pour the appropriate amount of new pool filter sand into the filter tank. Refer to your filter’s manual for the recommended amount. Be sure to use specially graded pool filter sand, not regular sand, which won’t provide the same level of filtration.

Step 6: Reassemble

Replace the tank’s lid, secure it, and turn on the pool pump. Be sure to check for any leaks.

Enjoy Your Filtered and Crystal-Clear Pool

And there you have it, the ultimate guide to backwashing your sand filter. By understanding how your sand filter works and knowing when and how to perform a backwash, you’re well on your way to enjoying a pool that’s as refreshing as it is inviting.

Remember, a well-maintained sand filter is the key to a beautiful pool, so keep those waters sparkling, and let the good times roll.

For any pool filter or maintenance needs, don’t hesitate to reach out to our expert team. We’re here to ensure your pool stays clean, clear, and ready for endless hours of summer fun.