Sand in pool, laterals look OK

[munsonbw]

Hi gang,

First let me say that this website has been a tremendous help for a new pool owner (house purchased with existing pool). Following the basic chemistry steps outlined here I only purchased bleach last year for pool maintenance. The previous owner left a few things that were all I needed to keep the pH in check.

I have two problems: air leak that appears to be coming from under the ground of the suction side and sand in the pool. I think I have the air leak identified, but I mention it just in case it relates to the sand. I tried the shaving cream, then water to identify the leak and only when I let the hose run into the ground next to the suction pipe did the air bubbles stop. Now the sand. At the beginning of last season I had to replace my multiport valve "handle cover assembly" (the one without the replaceable spider gasket on my Hayward S244T. Occasionally I would get a little sand here or there, but nothing really significant until late in the season. About a month before closing the sand loss was getting significant. I would end up with what looked like a dixie cup full of sand in the pool after running the pump for 10hrs or so. Over the winter I pulled the laterals out and inspected them and found them (to the best I could see) to be intact. I did notice that small grains of sand were stuck in the lateral slots. I put the sand I recovered from the filter back in and opened the pool. Unfortunately, the same story as last year.

To try and keep my test results short and sweet, here are some bullet point results:
* Filter and multiport valve worked nearly a full season without sand loss. When I bought the house in Nov. of the prior year, no sand issues
* laterals appear intact as does the stand pipe and lateral assembly
* sand appears small in grain size to me, but when measuring some with calipers I get .70-1.0mm. This seems to correlate to #20-40 sieve, assuming my measurements are rough. I do not know what is in my filter currently
* sand level seems low based on what I read in the hayward manual. I would guess about half full or so? Guessing at the weight when compared to a 50# sack of playsand i could believe there was ~300#, as it should be
* Unless I am redistributing sand already in the pool, sand is deposited during recirculate mode
* no water leakage out the waste line while in filter mode
* my pressure rarely moved much last year. 10psi is about normal and it might hit 15 before I backwashed, which was probably less than 4 times the entire summer.

What do you guys think? The sand I am picking up, as seen out the discharge line, does not look like the kind of dirt we have here in Alabama. Therefore, I don't think I am picking up dirt from the suction side line. I am thinking the first step is to remove the sand and re-check the laterals again. After that I am worried I am just throwing money at ideas, but I guess sand is next followed by a new multiport valve top. Thoughts?

Thanks
ben

 

[duraleigh]

Welcome to the forum

The amount of sand in your filter is a little confusing....you should be 2/3 full. Don't really think that is the issue.....just confirming how much sand is in there.

Something has changed since you ran successfully for a year without sand. From your narrative, it seems like you have removed the laterals after the season it was running well, right.

I would suggest you remove the sand and then inspect the seating of the hub and standpipe to make sure all is fitting correctly. That S244 is one of the most popular and reliable filters available I suspect your issue may be something just not seated perfectly.

You could also take the top off the multiport and check the gasket for correct fit but I doubt that is the issue.

 

[munsonbw]

Thanks for the reply, Dave.

Sorry for the long wording, but at the very end of last season I started seeing sand in the pool. At first I thought it was some kind of algae and spent a week slamming the pool only to finally check the actual debris and notice it was gritty. Silly me. I would estimate the filter ran for ~1 calendar year without issue, then 1-2 months with sand loss. That is what prompted me to inspect the laterals. I do agree with your point about something changing. If the sand grain size were the issue it would have surfaced a lot sooner than it did.

I did inspect the multiport gasket. It had some grains of sand embedded in it. May 5-10, that kind of number. Otherwise it looked in good shape. No tears or cracks.

I'll take your suggestion and pull the sand and re-inspect the lateral assembly. I'll also take another look at the sand volume. Have you ever heard of a filter losing sand when it was underfilled? Logic would say this would have nothing to do it, but what do I know.

Thanks!

 

[pooldv]

A couple of years ago we were getting some sand in the pool and we don't have a sand filter. Turned out to be ants messing around under the pool coping and getting sand into the pool. Some Home Defense sprayed around the coping took care of it.

 

[munsonbw]

pooldv,

Oh I hope its not ants. We have a real bad problem in Alabama with fire ants. Probably the same for you in Texas. I have had them around the pool but I haven't seen any activity this year. Good thing to check out though. Little buggers.

 

[pooldv]

Yep, we have all we need over here! Funny thing, I was emptying the skimmers today and the ants are busy! Sand in my robot. Just finished spraying around the pool.