Introduction
Noticing cloudy water or poor filtration despite running your pump? It might be time to clean your pool filter grids. If you own a Diatomaceous Earth (DE) filter, the grids inside need periodic cleaning to keep your pool crystal clear and your system running efficiently. In this guide, you’ll learn exactly how to clean pool filter grids step by step, helping you extend the life of your filter and avoid costly repairs.
Why Cleaning Pool Filter Grids Matters
DE filters use a series of fabric-covered grids coated with diatomaceous earth powder to trap fine particles from the water. Over time, these grids become clogged with:
- Dirt and debris
- Algae and oils
- Minerals and fine contaminants
When the grids are dirty:
- Water pressure rises, indicating reduced flow
- Pump performance drops
- Water clarity decreases
- Backwashing becomes less effective
Regular cleaning ensures:
- Optimal filtration and circulation
- Longer equipment lifespan
- Lower chemical usage
- Fewer issues with cloudy or green water
Step-by-Step Guide to Cleaning Pool Filter Grids
Step 1: Turn Off the Pool Pump
Safety first. Shut off the pool pump and ensure all electrical timers or breakers are switched off to prevent accidental operation during the cleaning process.
⚠️ Caution: Never open the filter tank while the pump is running.
Step 2: Release Air Pressure from the Filter
Locate and open the air relief valve on the top of the filter tank to release built-up internal pressure. This prevents dangerous pressure bursts when opening the tank.
Step 3: Open the Filter Tank
Most DE filters are either clamp-style or bolt-style tanks. Loosen the clamp or bolts securing the top and carefully remove the filter lid.
💡 Tip: Keep track of nuts, bolts, and O-rings for reassembly later.
Step 4: Remove the Filter Grid Assembly
Inside the tank, you’ll find the entire grid manifold assembly. Gently lift the grid assembly out of the tank and place it on a flat surface.
- These assemblies can be heavy and slippery—use both hands and move carefully.
- Watch out for remaining DE sludge or water inside the tank.
💧 Optional: Use a shop vac to remove leftover DE or debris from the bottom of the tank.
Step 5: Hose Off Loose Debris
Use a garden hose with a spray nozzle to rinse off the filter grids. Spray between the pleats and rinse all sides thoroughly to remove loose DE powder, dirt, and oils.
- Avoid using a pressure washer—it can damage the grid fabric.
- Take your time to clean between each fin or pleat.
Step 6: Soak Grids for Deep Cleaning (Optional but Recommended)
For deep cleaning or stained grids, soak them in a filter cleaner solution or mild acid wash:
- Use a large container or garbage bin filled with warm water.
- Add a commercial filter cleaning agent or a solution of 1 part muriatic acid to 5 parts water.
- Soak the grids for 2 to 6 hours, depending on buildup.
⚠️ Caution: Always add acid to water—never the other way around. Wear gloves and eye protection.
After soaking, rinse the grids thoroughly to remove all chemical residue before reassembly.
Step 7: Inspect the Grids
While the grids are out:
- Check for tears or holes in the fabric
- Look for cracked or broken plastic frames
- Make sure all fittings and manifolds are intact
If any part is damaged, replace the grid or manifold before reinstalling.
💡 Tip: Replace the entire grid set every 5–7 years or as recommended by the manufacturer.
Step 8: Reassemble and Return Grids to Filter Tank
Place the cleaned (and fully rinsed) grids back into the tank. Ensure the manifold is properly aligned and centered.
- Double-check that the air relief valve is closed.
- Reattach the tank lid securely using clamps or bolts.
- Lubricate the tank O-ring with pool-safe lube before tightening to ensure a good seal.
Step 9: Recharge with DE Powder
After cleaning, you need to add new DE powder to the skimmer while the pump is running.
- Consult your filter’s manual to determine how many pounds are needed.
- Typically, 1 lb of DE powder is added for every 10 square feet of filter area.
- Mix DE powder in a bucket with water first, then pour into the skimmer.
⚠️ Never run a DE filter dry—it can damage the grids immediately.
Step 10: Restart the Pump and Monitor Pressure
Turn the pump back on and open the air relief valve to let trapped air escape. Close the valve once water starts flowing.
- Monitor the filter pressure gauge
- Normal operating pressure should be similar to what it was after the last cleaning
- Note the reading for future reference
Common Mistakes to Avoid
1. Forgetting to Add DE Powder After Cleaning
Running a DE filter without powder damages the grids quickly.
✅ Always recharge the filter with the correct amount of DE.
2. Using High-Pressure Water
High-pressure hoses or power washers can rip the filter fabric.
✅ Use a standard garden hose with gentle spray to clean.
3. Reassembling a Dirty Manifold
Even if the grids are clean, a dirty manifold can contaminate your clean system.
✅ Clean and inspect the manifold thoroughly during every cleaning.
4. Not Soaking Stained or Oily Grids
Rinsing may not remove all contaminants.
✅ Soak grids periodically for deep cleaning.
5. Reinstalling Damaged Grids
A small tear lets debris bypass the filter, leading to cloudy water and equipment strain.
✅ Replace damaged grids before restarting your system.
Extra Tips & Pool Hacks
- Clean your grids every 3–6 months, or when the pressure rises 8–10 psi above the starting point.
- Mark your filter housing with the last cleaning date for easy tracking.
- Use a garden sprayer with filter cleaner for targeted cleaning without full removal between deep cleans.
- Keep a spare set of grids on hand for fast swaps during peak season.
🧼 Related Tip: [Learn how to maintain pool water clarity] to keep your entire filtration system in top shape.
Conclusion
Cleaning your pool filter grids is a crucial part of DE filter maintenance. With the proper tools, a bit of time, and the right approach, you’ll ensure your pool stays clean, safe, and efficient. Make this part of your regular pool care routine to prevent cloudy water, reduce chemical usage, and extend the life of your pool equipment.
👉 Bookmark this guide for your next DE filter cleaning session!