How to Backwash a Sand Filter

How To Backwash A Sand Filter

For routine maintenance, a sand filter is one of the easiest of the three types of pool filters to keep clean. Instead of manually cleaning the system like you do with a cartridge filter, you use water from your pool to rinse dirt and debris from the filter sand.

The water discharges through your backwash hose and can irrigate your lawn or other areas of your property. As an alternative, you can backwash your pool water into your home’s sanitary sewer cleanout, usually located next to your house. Contact your local authorities with questions about where you can legally backwash your pool water. Local, state and federal regulations prohibit discharging backwash into storm drains.

How Often Should I Backwash?

A good rule of thumb is to backwash once the pressure displayed on your pressure gauge is 8-10 psi over the starting level. Backwashing after heavy rains, treating for algae, or when trying to clear cloudy water will keep your filter working efficiently.

The Backwashing Process

Backwashing your sand filter is an easy process. All sand filters use the same principle for backwashing, the configuration may vary from manufacturer and model.

  1. Shut off pump motor and roll out backwash hose (if you have it).
  2. Twist and unlock the plunger T-handle, then pull and twist the plunger upward 2 - 3 inches.
  3. Open the air bleeder assembly on your filter and turn pump on.
  4. Watch the pressure gauge for spikes.
  5. After the hose fills with water, backwash your sand filter for 2 - 3 minutes, or until water runs clear.
  6. Shut off the pump motor and push the T-handle back down into locked position.
  7. Turn your pump back on and note the lower pressure.

Note: To backwash using a multi-port valve, refer to labeling on the valve itself or in the manufacturer’s instructions.

A Job Well Done

Products like Leslie’s Sand Filter Revitalizer can be used in conjunction with backwashing to remove caked-on oils and organic materials that are left after backwashing. Follow the label directions for use. If you have any more questions about backwashing your sand filter, visit your local Leslie’s store. We have experts on hand to answer all your questions and more!

Essential Products

Backwash Hose

Backwash Hose

Pressure Gauge

Pressure Gauge

Zeolite Sand

Zeolite Sand

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Leslie’s makes every effort to provide accurate recommendations based upon current ANSI/APSP/ICC-5 2011 (R2022) standards, but codes and regulations change, and Leslie’s assumes no liability for any omissions or errors in this article or the outcome of any project. You must always exercise reasonable caution, carefully read the label on all products, follow all product directions, follow any current codes and regulations that may apply, and consult with a licensed professional if in doubt about any procedures. Leslie’s assumes no legal responsibility for your reliance or interpretation of the data contained herein, and makes no representations or warranties of any kind concerning the quality, safety, or suitability of the information, whether express or implied, including, without limitation, any implied warranties of merchantability or fitness for a particular purpose.