Backwash Hayward 6020 with Hayward SP722D slide valve??

[scomea]

Hello,
New pool owner here and I have a Hayward SP722-D slide valve attached to DE6020 DE filter. I can't find a manual on the internet for the and want to make sure that I'm back washing and charging correctly. This will be my first time to back wash. Here is what I think the sequence may be: Turn off pump, unlock valve and pull up, turn on pump for 2 minutes, turn off pump, push slide down and lock, turn on pump and add 6 lbs. of DE to skimmer. Is this the correct sequence?

Also, is there a way to rinse the SP722D slide valve? And, if you were to replace this valve, what valve would you use?
Thanks in advance

 

[proavia]

I'm pretty sure the "SP722-D" refers to the nut on top by the handle. An SP722 (without the "D") is a Hayward ball valve. You may have this: Hayward Slide Valve 2 SP410X Parts - INYOPools.com

Here is a tutorial on cleaning a DE filter: DE Filter Cleaning Tutorial
See "Step: 1... - for backwashing. Since you don't have a multiport valve with a sight glass, you would backwash until the water coming form the backwash hose is clear. Maybe do this 2-3 times - alternating between backwash and filter (turn the pump off before switching valve settings.

Not sure exactly what you mean by "rinse". Is the valve difficult to turn and/or pull/push? You can take the valve apart, clean it up and re-lube the O-rings.

The slide valve could be replaced with a multi-port in the future. But if the present valve is still serviceable, save the money. I have heard that some people don't backwash there DE filters. Instead, they opt to take them apart and do a complete cleaning.
The DE filter cleaning tutorial I linked above will give you an idea of the process.

 

[scomea]

Thanks for the clarification Gene. And yep, SP722-D is the top nut. New grids and DE were installed March 1st. PSI was recorded at 13 and now it's 21. I think it's got a few more hours till a complete cleaning.

 

[proavia]

Yes, up to you whether to backwash or tear it down. Just make sure not to overcharge it with DE after a backwash - I understand that's a common issue.

Here's a step-by-step for rebuilding the slide valve: How To Replace the Hayward Slide Valve Internal Shaft O-Ring - INYOPools.com

 

[scomea]

I back washed and had 1 psi after back wash and prior to adding DE. After adding 6lbs of DE, the psi settled at 17psi at 3100 rpm and 9.5psi at normal running speed of 2350 rpm. New filter material was installed in March. Am I in the zone?

 

[proavia]

Sounds good. You now have a "clean" pressure. When the pressure rises 20-25% above that, it's time to backwash or tear down the filter again. Always use the "clean" pressure for whichever process you use (backwash or teardown).

Did you do the backwash 2-3 times, backwashing until the water ran clear each time?

Your clean pressure may be a tiny bit lower after a complete tear down than after a backwash. This is do to the filter being completely void of DE - as opposed to some DE remaining in the tank after a backwash. Next time you do a complete tear down, note that clean pressure and compare to the backwash clean pressure. Comparing your present backwash pressure and the pressure after the new grids were installed indicates that slight difference.

What did you mean by "rinse" the slide valve? The INYOPools link I posted above gives an idea on how to take the valve apart. Yours may just need the o-rings lubed. However, when you take it apart, do it when you have time to run to the ps to get an o-ring kit -- cause if you do it after they close and you need o-rings.... well you get the idea (ask me how I know this ).