DE Filter Strangeness...

RASelkirk

Well-known member
Jul 11, 2015
62
Port Neches, TX
#1
Hi All,

I swapped over to a DE filter from sand almost 15 years ago. Went through the grid cleaning every year, between cleanings it only needed backflushing 2 or 3 times a year. About 2 years back, I started seeing what looked like filter media in the pool, so I ordered some new elements and changed them out (didn't help). Still seeing grayish-beige "dust" in the pool's bottom whenever the Zodiac G3 is not running. This past year, it seems like I'm BF'ing at least monthly if not sooner. Sometimes I can BF one day and overnight the filter has gained 8#. Does the quality of the replacement elements make a difference? They came off of E-Bay: " Pleatco PFS1836 36 sqft Filter Grid Set Pentair FNS36 Hayward DE3620 FS2003"...

Russ
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#2
Russ, Pleatco generally has reliable replacement filters. I use them myself. Let's start with a basic question to make sure we rule out the easiest ….. are you 100% sure it's not algae (or dead algae) that's settling and clogging the filter? A dust appearance and pressure increase are early signs. Can you post a recent set of test results just so we can confirm and move to the possible scenario?

Just to confirm, since you're on a SWG, nothing else has been added to the water correct?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
10,552
Bedford, TX
#4
Russ,

I agree with Pat.. You have all the signs of an algae bloom... Nothing else that I know of will make your pressure increase over night by 8 lbs...

I don't believe that your problem has anything to do with the quality of your grids.

I suspect that this happened last summer and you never got rid of it... When is the last time you did an OCLT??

Thanks,

Jim R.
 

RASelkirk

Well-known member
Jul 11, 2015
62
Port Neches, TX
#5
What's an "OCLT"? That I don't know could possibly mean never. o_O It could be algae, usually (here in SETX) it's mustard algae which is easily discernible visually. I used to get it all the time with the chlorine/sand setup. The pool is a couple years past it's last repaint, if you brush hard enough you'll see whitish powder come off the walls. I usually only brush a couple times a year. The water is so pretty it's hard to imagine algae, but that would definitely explain the pressure problem. Since going to DE/salt, I've not really added anything other than occasional adjustments to PH and hardness...

Thanks!

Russ