Nautilus DE filter Strainer, air vent getting clogged

mac4lyfe

LifeTime Supporter
Jun 8, 2007
212
0
Houston, Texas
#1
I'm trying to figure this out. My Nautilus DE filter pressure keeps going up after several hours (5 hours). I've changed the DE grids to new. I've noticed by taking the filter apart that the Air Strainer on top usually gets very clogged with debris (pine needles, bugs, crap, etc) Also the strainer is pressed down flat versus round shape. I bought a new strainer and the same thing happened where it becomes clogged after a few hours and the pressure goes from 18psi (normal) to 30-35psi (high). If I backwash the pressure goes down for a few hours only to go back up after about 5 hours. Because the air strainer is pressed flat, debris gets stuck in it easily. Anybody else experience this?

The pool is relatively clean, no algae, dirt. theres alot of trees nearby and leaves and needles must be getting trapped. I've installed pool socks and mesh net but somehow debris keeps getting on the air strainer. The DE filter grids look very good. Why would this strainer get clogged, why does it clog so quickly even with skimmer socks and why won't backwashing cure the problem?

Any help would be appreciated.
 

JasonLion

LifeTime Supporter
Platinum Supporter
TFP Expert
May 7, 2007
37,879
5
Silver Spring, MD
#2
If you are having a great deal of pollen right now that could account for it. Pollen can clog up a DE filter quite quickly. Skimmer socks help but they don't catch the really fine pollen.
 

mac4lyfe

LifeTime Supporter
Jun 8, 2007
212
0
Houston, Texas
#3
Thanks for the reply. The strange thing is that the DE filter grids are NOT getting clogged. It's only the strainer vent and that's what causing the pressure increase. I used skimmer nets today and it removed some small particles but the pressure still went up. I haven't opened the filter but I'm sure the air strainer is clogged again.

Anybody experience this? Any ideas how the strainer gets clogged but not the grids?

Thx
 

mac4lyfe

LifeTime Supporter
Jun 8, 2007
212
0
Houston, Texas
#4
I failed to mention that I replaced my filter grids a few weeks ago with the same Unicel model grids. Apparently something's wrong with the new grids. I used the old grids and there's no pressure problems. I now am using 6 old grids and 2 new grids and so far so good.

Any idea why the new grids would cause pressure problems? It takes a few hours but the pressure keeps building on the new grids until the filter starts squealing (>35 psi). Did I get a bad batch of filters?
 

Denali

Well-known member
May 1, 2008
70
0
#5
Very strange. I have never heard of new grids being defective in that way. I would return them for a new set.

The air strainer plugs because it's the path of least resistance for the water. Not all filters have the air strainer and I've never seen a need for them. Perhaps I'm missing something with them but I found they are just a pain (strainer comes off, DE goes back into pool.

Let us know what happens with the new grids.
 

mac4lyfe

LifeTime Supporter
Jun 8, 2007
212
0
Houston, Texas
#6
I reinstalled the old filters and no problems at all. Very strange that the new filters gave me problems. I actually have 6 old filters and 2 new ones installed since 2 old filters were cracked.

The new filters are the same brand but they seem to hold water alot tighter. That could be the problem. Maybe they were wound tighter.