Pool Sand Demystified: Everything You Need to Know About Sand Filters

Thinking about changing your pool sand but unsure where to start? You’re not alone. Whether you're a seasoned pool owner or just opened your first backyard oasis, understanding pool sand is key to crystal-clear water. Many pool owners struggle with murky water, weak filtration, or skyrocketing maintenance costs—all of which often trace back to one culprit: worn-out or incorrect filter sand.

This guide will walk you through everything you need to know about pool sand, including how it works, when to change it, and how to replace it properly. Plus, we’ll link you to trusted products from Aqua Pool Supply to make the job a breeze.

What Is Pool Sand and Why It Matters

Pool sand, especially high-grade silica sand, is the lifeblood of your sand filter system. Its job? Trapping debris, dirt, and oils from your pool water as it passes through the filter tank. A properly functioning pool sand filter ensures clear, clean, and swim-ready water.

How Does a Pool Sand Filter Work?

• Water enters the top of the filter tank.
• It seeps through the bed of tightly packed sand.
• As it flows through, dirt and debris are caught between the grains.
• Clean water exits through laterals at the bottom and returns to the pool.

Over time, the sand becomes clogged with debris or rounded off, reducing its ability to trap particles. That’s when you’ll notice pressure build-up, cloudy water, or a struggling pump system.

When and How Often to Change Pool Sand

The general rule of thumb is to replace your filter sand every 3 to 5 years. However, this can vary based on pool usage, weather conditions, and filter performance. Here are some signs it’s time to swap out the sand:

• Water stays cloudy despite chemicals being balanced
• Filter pressure remains high after backwashing
• Pool requires frequent vacuuming
• You notice sand blowing back into the pool

How to Change Sand in a Pool Filter (Step-by-Step)

What You’ll Need:

• Silica filter sand (check your filter’s manual for how much you need)
• Screwdriver or wrench (for opening the filter)
• Shop vac or scoop
• Garden hose
• New filter O-ring or gasket (optional but recommended)

Step-by-Step Guide:

1. Turn off the pump. Shut off power to the system to avoid accidents.
2. Drain the filter tank. Use the drain plug at the base to empty out any remaining water.
3. Remove the valve or filter head. This gives access to the old sand.
4. Scoop or vacuum out the old sand. Be careful not to damage the laterals inside.
5. Rinse the tank. Use a garden hose to clean out any leftover debris.
6. Fill halfway with water. This protects the laterals from the weight of falling sand.
7. Pour in the new sand. Use a funnel or scoop, slowly adding the required amount.
8. Reassemble the filter and backwash. Once everything is sealed, run a backwash cycle to flush out fine particles.

How Much Sand Does Your Pool Filter Need?

The amount of sand depends on the size and model of your filter. Here's a quick reference:

Always check your manufacturer's manual or contact Aqua Pool Supply for confirmation.

Extra Tips for Optimal Filter Performance

• Backwash weekly during peak swim season to remove trapped debris.
• Use a pool clarifier if water appears hazy after sand replacement.
• Don’t overfill the tank with sand—it can damage the internal parts.
• Inspect O-rings and gaskets during sand replacement for cracks or wear.

Frequently Asked Questions About Pool Sand

How often should I change sand in my pool filter?

Typically every 3 to 5 years, or sooner if your pool water is consistently cloudy or your filter pressure is unusually high.

What kind of sand should I use in my filter?

Use only #20 grade silica sand, specifically labeled for pool filters. Never substitute with playground or construction sand.

Can I use glass or zeolite media instead of sand?

Glass and zeolite are alternatives but may not be stocked by Aqua Pool Supply at this time. Stick with silica sand for guaranteed compatibility.

How do I know how much sand my filter needs?

Check your filter's manual or look up your filter model online. Tank size directly determines how much sand is required.

What happens if I don’t change my pool sand?

Old sand loses its filtering ability, leading to cloudy water, poor circulation, and stress on your pool pump.

Time for a Refresh? Let’s Get You Filter-Ready

Knowing when and how to change your pool sand can save you hours of maintenance and hundreds of dollars in repair costs. Whether you're swapping out old sand or just starting your filter journey, Aqua Pool Supply has everything you need—including 20-grade silica sand and expert support to help you every step of the way.