How To Properly Backwash A Hayward ProGrid DE Filter (Step-By-Step)

When To Backwash

Backwash the ProGrid when pressure rises 8–10 PSI above the recorded clean pressure. Do not backwash on a fixed schedule regardless of pressure, and do not wait longer than necessary — high pressure means reduced flow and stressed grids.

After recording your clean pressure at startup, set the red indicator arrow on the gauge pressure ring to show the backwash threshold. When the gauge needle reaches or passes that mark, it is time.

Backwash Procedure: Six-Position Vari-Flo Valve (SP0710XR50 or SP0715XR50)

This valve type has positions: FILTER, BACKWASH, WASTE, RECIRCULATE, RINSE, and CLOSED.

1. Shut off the pump. Do not skip this step. Moving the valve under pressure stresses the valve spider gasket and can damage it.
2. Set the filter control valve handle to BACKWASH.
3. Start the pump. Backwash for approximately 2 minutes, or until the water exiting the waste line appears clear. On the first backwash after startup, the water may take longer to clear.
4. Shut off the pump.
5. Set the control valve to RINSE.
6. Start the pump and operate for 20 seconds. The RINSE position sends water through the filter in the normal direction but routes it to waste. This seats the remaining DE evenly and flushes the valve before returning to pool mode.
7. Shut off the pump.
8. Set the control valve to FILTER.
9. Add fresh DE through the skimmer per the pre-coating procedure below.

Backwash Procedure: Four-Position Selecta-Flo Valve (SP0740DE)

This valve type has positions: FILTER, WASTE, BACKWASH, and POOL OR SPA BOOST. There is no dedicated RINSE position.

1. Shut off the pump.
2. Set the control valve to BACKWASH.
3. Start the pump and backwash for approximately 2 minutes, or until water out the waste line is clear.
4. Shut off the pump.
5. Set the control valve to FILTER.
6. Add fresh DE through the skimmer.

Because this valve has no RINSE position, it is especially important to add DE carefully and slowly to minimize the pre-coat puff returning to the pool.

Backwash Procedure: Two-Position Slide Valve (SP0410X502S)

This valve has only FILTER (handle down) and BACKWASH (handle up).

1. Shut off the pump.
2. Move the slide valve to BACKWASH (handle in UP position).
3. Start the pump and backwash for approximately 2 minutes or until waste water clears.
4. Shut off the pump.
5. Move the slide valve to FILTER (handle DOWN).
6. Add fresh DE through the skimmer.

Adding Fresh DE After Backwash (Pre-Coating)

Add DE to the system through the skimmer as fast as the plumbing will take it. Use the exact amount specified for your model:

• DE2420 (24 sq ft): 3.0 lbs
• DE3620 (36 sq ft): 4.5 lbs
• DE4820 (48 sq ft): 6.0 lbs
• DE6020 (60 sq ft): 7.5 lbs
• DE7220 (72 sq ft): 9.0 lbs

After adding DE, record the gauge reading. This is your new clean pressure. Line up the green arrow indicator on the pressure gauge with this reading. When pressure climbs 8–10 PSI above it, backwash again.

If you see a visible white cloud at the returns right after adding DE (the "pre-coat puff"), you can add the DE with the valve set to RINSE (Vari-Flo) to route that water to waste instead of the pool. Return to FILTER once the returns clear.

What Backwash Cannot Fix

Backwashing removes loose DE and captured dirt. It does not remove:

• Body oils and sunscreen films embedded in the grid cloth
• Calcium and mineral scale deposits
• Algae byproduct staining in the cloth fibers

If pressure climbs back to a high reading within hours of a fresh backwash and DE charge, or if clean pressure has gradually risen compared to historical readings, the grids need a chemical soak. See the manual cleaning guide.