Your pool’s filter is the unsung hero of crystal clear water, and if you have a sand filter, you already know why it’s so popular. Sand filters are durable, low-maintenance, and effective at catching dirt and debris. But like any piece of pool equipment, they need a little care to keep performing their best.

Here’s everything you need to know about maintaining your sand filter.


What Does a Sand Filter Do?  

A sand filter works by pushing water through a bed of special pool filter sand. As water flows through, dirt, debris, and small particles get trapped in the sand, and clean water is returned to your pool.

Sand filters are known for their simple operation and can keep your pool clear for years with proper upkeep.

Essential Sand Filter Maintenance  

1. Backwash Regularly  

Backwashing is the process of reversing the water flow through the filter to flush out dirt and debris.

When to Backwash:

• When the pressure gauge is   8–10 PSI higher than normal
• After heavy pool use or storms
• When water looks cloudy

Sand filters are durable and efficient, but over time, the sand loses its ability to trap debris properly.

On average, filter sand should be replaced every 3 to 5 years, but a few signs can tell you it’s time sooner:

• Water stays cloudy even after running the filter because old sand can become smooth and round, losing its sharp edges that trap debris.
• Increased pressure on the filter gauge: If backwashing doesn’t lower the pressure, the sand might be clogged or compacted.
• Frequent need to backwash: If you’re backwashing more often than usual, it could mean the sand is no longer filtering effectively.
• Sand is returning to the pool: Worn-down or clumped sand can bypass the laterals and end up in the pool.
• Time elapsed: Even if you don’t notice the above symptoms, replacing sand every few years ensures peak performance

3. Monitor Pressure Gauges  

Your sand filter has a pressure gauge, which is your first warning sign of an issue.

• High Pressure: This means the filter is dirty—time to backwash.
• Low Pressure: This could indicate a pump or suction problem.
  

4. Winterize If Necessary  

If you live in a cold climate, winterizing your sand filter is crucial:

1. Backwash and rinse the filter.
2. Remove the drain plug to let water escape.
3. Store the multiport valve in a neutral “Winter” or “Closed” position.


Why Proper Sand Filter Care Matters  

A well-maintained sand filter:

• Keeps water crystal clear
• Reduces chemical use
• Extends the life of your pool pump and other equipment