Knowing when and how to backwash pool filter systems—whether DE or sand—is one of the most important steps to keeping your pool water clear and circulation strong. If you own a Hayward ProGrid, Pentair FNS Plus, or Jandy JS Series, understanding backwash frequency will help you avoid pressure problems, cloudiness, and unnecessary wear on your filter. In this guide, we’ll break down how often to backwash, what signs to look for, and how to keep your system running at peak efficiency.
Why You Need to Backwash Pool Filter Systems
To backwash pool filter systems means reversing water flow to flush out trapped dirt and debris. This clears the internal media (grids or sand) and restores proper flow and filtration. Without regular backwashing, your system can become clogged, resulting in increased pressure, weak circulation, cloudy water, and higher chemical demand.
Backwashing a DE Filter: How Often is Enough?
For DE filters such as the Jandy DEV or Pentair Quad DE, you should plan to backwash:
Roughly once a month during swim season
Whenever filter pressure rises by 8–10 PSI
After heavy debris events or storms
Don't forget—after each DE backwash, you'll need to add fresh diatomaceous earth powder to recoat the grids. Also, clean the internal filter grids at least once or twice per season to prevent buildup of oils or scale.
EP Minerals Celatom Diatomaceous Earth Filter Powder | 25 lbs. | DE25
$24.99
$39.99
Diatomaceous Earth (DE) is a completely natural substance that effectively filters contaminants in your pool, capturing particles as small as 2 to 5 microns. Comprising microscopic, coffin-shaped hollow particles resembling miniature sponges, DE forms a porous powder. This unique structure… read more
How Often to Backwash a Sand Filter
Sand filters, such as the Hayward ProSeries or Pentair Tagelus, require backwashing less frequently but still need regular attention. Backwash these filters:
Every 4–6 weeks
When pressure increases by 8–10 PSI
After heavy leaf debris or pool parties
Unlike DE filters, sand systems don’t need powder replacement—but the sand itself should be replaced every 3–5 years for best performance.
Signs It’s Time to Backwash Pool Filter Equipment
Whether you have DE or sand:
Higher pressure readings on your gauge
Weaker return jet flow
Cloudy water despite good chemistry
Air bubbles or noisy operation
If you're backwashing too frequently and still having problems, it could be due to damaged grids, broken laterals, or failing valve parts.
Need Grids, Backwash Hoses, or Filter Parts?
If your filter is underperforming even after backwashing, the problem might be internal. A damaged grid, worn O-ring, or cracked multiport valve can all cause issues. Instead of guessing, use the Replacement Parts Search Tool on our homepage. Just enter your filter brand and model—like Hayward DE6020 or Pentair FNS Plus—and pull up a clickable diagram showing every part with direct links.
From filter grids and laterals to backwash valves and O-rings, it’s the fastest way to find exactly what you need.
Blue Devil 25' Heavy Duty Backwash Hose With Clamp | 2" | B8259
$19.99
$24.99
The Blue Devil Valterra 25' Backwash Hose with Clamp B8259-25' is designed to assist in the effective removal of wastewater from pool filters, helping maintain peak filtration performance. Constructed from durable 22 mil reinforced vinyl, this 2-inch by 25-foot hose is… read more
Final Thoughts: Stay Ahead of Filter Problems
Backwashing isn’t just a chore—it’s a key part of keeping your pool safe, clear, and low-maintenance. Whether you’re using a DE filter that needs powder recharge or a sand filter that just needs a quick flush, keeping an eye on pressure and cleaning at the right time helps your entire system last longer.
Don’t wait until your water turns cloudy—keep your filter on schedule, and if something’s not working right, head to our homepage and use the parts finder to get your system back to full flow.
