Is 1 Backwash Sometimes Not Enough?

[NullQwerty]

Hey folks,

I'm new to Sand Filters. Just got a new 350 lb one, which has been in service 1 week cleaning a very dirty pool. The first time I turned it on the PSI was around 9, give or take 1. The first couple of times I backwashed, it brought the pressure back down to 10 psi. But now when I backwash, it only drops to 12 psi when it's done. My procedure has been backwash for 2 minutes, then rinse for 30 seconds. Should I repeat the procedure if it doesn't bring it down to 10?

Thanks

 

[scooperhsd]

I backwash mine until the water in the sightglass is clear and has most of the black particles out of it, then rinse (30 sec - 1 minute), then do another 1-2 minute wash, followed by another rinse, then back to normal filter mode. Usually I don't do the second wash / rinse and let it go at once if it didn't take very long to get clear. But I really use the sightglass for Determining when to quit washing, and not time per se.

 

[Txmat]

I use time. 1 min backwash, turn pump off for 1 min, repeat 2 more times, rinse for 30 seconds, pump off for 30 seconds, then back to filter.

 

[linen]

I also use the sight glass, I backwash until it is totally clear. Then rinse until clear. Using time may not always get your filter clean, or in some cases will be overkill IMO.

 

[X-PertPool]

I believe back washing multiple times will help loosen up stubborn or heavy debris from the sanded. I think it's mostly the jostling of the water inside the tank when moving from backwash to rinse over and over that can break something stubborn free. I could be totally wrong just my theory

 

[topher]

I wish I had a rinse function my old filter did. but my new -crappy - used one I got for 25 bux doesn't... will be getting a new one this winder. (i hope)

 

[X-PertPool]

I wish I had a rinse function my old filter did. but my new -crappy - used one I got for 25 bux doesn't... will be getting a new one this winder. (i hope)

not that big of a deal, rinse is just filter to waste

 

[NullQwerty]

Thanks for the info everyone!

 

[NullQwerty]

So I backwashed a second time. So that's a total of 4 minutes plus 1 minute of rinsing. Remained at 12 PSI. Guess 12 PSI is my new base point. Maybe 10 was just because it was brand new sand or something.

 

[linen]

Only other thing I can think of that the change might be due to is less resistance to flow in your supply line, or more resistance to flow in your return line now.

 

[NullQwerty]

Yeah, no clue here. I switched it to recirculate and on recirculate it drops to 10 psi.

 

[X-PertPool]

If you only have a 2 psi difference from recirc to filter then I'd say your okay.