How To Backwash a Hayward DE Filter

WRITTEN BY:  Inyo Pools

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A Diatomaceous Earth (DE) Filter cleans your pool water by passing the water through a set of normally 8 grids. Each of these grids is covered with a layer of DE powder. If your pools water is not clear and/or your filter's pressure gauge is reading about 10 psi higher than normal, It's time to backwash your filter to strip the current layer of DE power off the grids and replace it with new powder. Although this guide is specific to a Hayward Pro Grid DE Filter, many of its steps are applicable to most DE filters.  Note: About once a year you should take the grids out of your DE Filter and clean them more thoroughly. See our guide on "How To Remove and Clean Hayward DE Filter Grids" for more information.

Video

Step by Step

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Step 1

BUY DE POWDER - You will need about 4-6 pounds of DE Powder to replace the old DE Power that is striped off the grids during backwash. Buy this ahead of time so it is available when you need it. The DE Powder is available in large bags (like 25#s) which will last for 4-6 separate backwashes.

Step 2

ROLL OUT WASTE HOSE - Roll out the backwash hose to drain the pool water and old DE Powder away from your pool equipment.

Step 3

TURN PUMP OFF - If your pump is on, turn it off at the power switch or ideally at the circuit breaker box. You should not change modes of operation on the Multiport Valve with the pump on. You will damage the spider gasket in the Valve.

Step 4

ROTATE MPV HANDLE TO BACKWASH - Rotate the Multiport Valve Handle to the "BACKWASH" position. Be sure to depress the Handle all the way down and hold it down as you rotate it.

Step 5

TURN PUMP ON AND BACKWASH - Turn the Pump back on and backwash for 2-3 minutes to strip the old DE Powder and contaminates off the filter grids. The flow of water during a Backwash cycle is reversed from that of the Filter cycle and dirty water and old DE Powder is washed out the waste line. Note: This process will lower your pool's water level slightly. If it started low, you may have to add water to the pool with a garden hose.

Step 6

MONITOR SIGHT GLASS - As you backwash the filter, you should see the water in the sight glass change from cloudy to clear.

Step 7

TURN PUMP OFF - Turn off power to the pump again to set up for the "RINSE" cycle.

Step 8

ROTATE MPV HANDLE TO RINSE - Push down on the handle while rotating it to the "RINSE" position.

Step 9

TURN PUMP ON AND RINSE - Switch the pump back on for 30 seconds or so to rinse the grids from the normal Filter side of the grids. In this mode, water flow is switch back to flow in the same direction as it would in the Filter mode, except the water and any remaining residue is purged out the waste line.

Step 10

TURN PUMP OFF - Switch the pump off again.

Step 11

REPEAT BACKWASH AND RINSE - If it's been awhile since you backwashed your filter, you may want to repeat the Backwash / Rinse cycle again to get any stubborn DE Powder and contaminates out. Repeat steps #3 through #10. If not, continue to the next step.

Step 12

TURN PUMP OFF - Switch the pump off.

Step 13

ROTATE MPV HANDLE TO FILTER - Push down on the handle completely while rotating it to the "FILTER" position.

Step 14

TURN PUMP ON - Switch the pump back on to add new DE Power.

Step 15

ADD DE POWDER - Go to our guide on "How To Add DE Filter Powder"

Comments

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Anonymous  Posted: 06/30/2016 14:23 PM 

Clear and easy to understand... thank you so much.


Linda  Posted: 05/31/2016 13:52 PM 

Your site and videos have saved me so much time and money. I have been through 2 lousy pool services then decided to do it my self. I have learned so much from your site about proper pool maintenance I am confident enough to do it my self. If I hire another service I now know enough not to get taken advantage of. I am also very pleased with the robotic sweeper I purchased from you. Thank you!!!