getting sand in pool, but laterals are fine

VAwaterboy

Active member
May 10, 2014
27
Falls Church, VA
Sand is coming into my pool through the returns, so I opened up the filter and removed the sand. The laterals and vertical standpipe are fine; no damage at all. I also opened up the multiport valve and didn't see anything wrong with it either.

Now what? Does anyone have an idea what else could cause the problem? I am puzzled.:confused:
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
Are you using the correct sand? #20 silica pool sand? Any chance the filter has too much sand (about 2/3 full)? As far as the multiport is concerned, does the sand seem to flow back to the return jets when the multiport is in any position, or just a certain position(s) - if you can tell?
 

VAwaterboy

Active member
May 10, 2014
27
Falls Church, VA
Good questions. I have had Zeobrite in the filter for a few years and never had this problem before. The filter tank seemed to be less than 2/3 full. I can see that the Zeobrite particles are bigger than the openings in the laterals.

I have not noticed what position the valve is in when the sand is returning to the pool.

The only odd thing I see is that the air relief tube (I think that's the correct term) next to the vertical standpipe does not have a screen on it. The inside diameter of that tube is only about 1/8 inch, but I suppose sand could get in through that. Could that be the problem?
 

raynesci

Member
May 31, 2017
13
Freehold/NJ
I have a similar problem right now. I am still getting some sand in my pool, but what I found when I emptied the tank was that the laterals were fine, but the base of the lateral assembly had a hairline crack in it. This definitely was opening up when 300 lbs of sand was on top of it, as well as the pressure from the pump. I think the sand I am still getting is residual that was left in the returns, but that is besides the point for your problem. If you haven't already put everything back together, check the entire lateral assembly, including the base, for cracks. I have also seen suggestions that replacing the spider gasket can help with sand leaking in. It didn't work with me, and I don't really see how it pertains to a sand issue, but I guess it's worth a shot to take a look at it and see if it needs replacing anyway.
 

borjis

LifeTime Supporter
Aug 19, 2014
3,284
Pacific NW
Yes you really need to look at every millimeter of the entire assembly.

Lots of folks just glance it over thinking it's ok, when a crack somewhere might not even
show. So probe / poke around a bit to see if a crack somewhere is revealed.