Why are my laterals leaking sand into my pool

[Her pool boy]

I was getting a bit of sand in the pool last year so decided I would replace my laterals this spring, which I did. I bought 8 new laterals and replaced the old with new. I could not really find anything wrong with the old ones other than the white plastic looked brittle and tired. See photo of old and new.

After replacing the old with the new laterals I filled with sand and reconnected the filter head and plumbing. Started it up with the cover on. When I took the cover off I notice a bit of sand on the bottom underneath the outlets. I ran it for a few weeks and intermittently I get big waves of sand dump in the pool. In two weeks of running I vacuumed out half a bucket of sand.

Obviously not normal so removed all of the sand from my filter and pulled out the standpipe and laterals. I can not see anything visually wrong. So wondering why are my laterals leaking sand into the pool? Before I do anything else I am wondering if anyone has any advice on what might be going wrong or what I might do to help ensure no sand gets into the pool. Caulk?

I have made things much worst so any help would be appreciated.

Thanks.

 

[Texas Splash]

Tricky one. I'll toss out an array of items that might result in sand getting pushed back into teh pool. Maybe compare to things you've seen or done there:
- Broken lateral or bad connection at hub assy
- Damaged standpipe or poor connection to lower hub assy
- Wrong sand; must be #20 silica sand; some brands of sand (i.e. Quikrete) have been troublesome slipping through the slots.
- Vessel filled too high with sand getting into the top of the standpipe
- Pump too strong; doubtful this is your issue
- New sand not rinsed and/or compacted & settled enough.

That's my initial laundry list of things.

 

[Her pool boy]

Hey Texas Splash. On closer inspection of the laterals I notice a trail of soot down the side of one of the laterals. See photo

It appears that sand is getting past this lateral into the hub assembly. Probably best if I just replace everything but parts are hard to come by these days, especially for my old filter. Don’t really have the extra cash to buy a new filter right now. Would you use this flexible sealer (photo) around each lateral to ensure a tight seal? I know that will pretty much prevents me from ever changing my laterals again but it would probably be time for a new one anyway once that times comes around. Thoughts?

 

[Texas Splash]

Might as well give it a Hail-Mary toss and go for it. If you're going to try some sealer, I'd probably use the old laterals just in case it doesn't work.

 

[Her pool boy]

Is there a minimum amount of sand to use when testing? I do t want to load all of the sand back if it doesn’t work. Thanks.

 

[Texas Splash]

Is there a minimum amount of sand to use when testing? I do t want to load all of the sand back if it doesn’t work.

Well, optimal is about 2/3 full. While I suppose you could fill it only halfway or slightly less as an initial test, keep in mind it won't duplicate the weight of the sand. The full weight of (wet) sand is quite a lot of pressure on the laterals.

 

[1poolman1]

Hey Texas Splash. On closer inspection of the laterals I notice a trail of soot down the side of one of the laterals. See photo

It appears that sand is getting past this lateral into the hub assembly. Probably best if I just replace everything but parts are hard to come by these days, especially for my old filter. Don’t really have the extra cash to buy a new filter right now. Would you use this flexible sealer (photo) around each lateral to ensure a tight seal? I know that will pretty much prevents me from ever changing my laterals again but it would probably be time for a new one anyway once that times comes around. Thoughts? View attachment 411800View attachment 411804View attachment 411801

Silicon sealant (RTV) will seal just as well and will still be removable. Just let it cure a bit before reassembly.

 

[Her pool boy]

Silicon sealant (RTV) will seal just as well and will still be removable. Just let it cure a bit before reassembly.

I will give that a try

 

[Her pool boy]

I’ll let you know how it goes.

 

[Her pool boy]

After looking at everything I realized how dirty the centre hubs inlets were so I figured I’d give them a good clean with a magic sponge and a small edge screw drive to clean out all of the edges and channels.

I should’ve done that the first time but didn’t. As I was cleaning each inlet I could see where dirty/sand was passing into the hub obviously from even before I changed the laterals. Perhaps if I had done that first I won’t be in this situation but not sure if I just put everything back together again my problem will be solved. There are a lot of micro scratches inside the inlets, probably not the first time the laterals were changed on this filter. (But I don’t know that for sure as I bought the house with the pool and filter.)

Any one’s experience say that cleaning should do the trick? Or should I continue with my plan and use the RTV silicone?


I just don’t want to unload 300lbs of sand again and make sure when I finish this time it works.

Thanks for sharing any advise and experience.

S

 

[Texas Splash]

I would go ahead and add the silicone. It can't hurt and it won't be permanent so you can disassemble later if needed.

 

[Her pool boy]

Done and dusted.

I’ll let it cure for the recommend 24 hours and then load it up. Hopefully have it back up and circulated by tomorrow afternoon.

I am feeling confident that it will have solved the problem. I’ll post the outcome when I know how it is working.

 

[Her pool boy]

Had a question about filling. Would you put the laterals in on a small bed of sand with the centre hub still touching bottom, and then fill, or fill around the laterals?

 

[Her pool boy]

Was able to get all of the sand back in today and the pump has been running for about an hour with the pool filtering and so far no signs of sand. I put a skimmer sock over the first jet and did not see any sand. Fingers crossed I’ve solved the issue.

Some lessons I learn by having to do this job over again.

1. Replacing laterals is not as straight forward as most other things we do with our pools. Working through the small opening at the top of the filter creates some unique challenges.
2. Removing the sand needs a strong vacuum and a strong back as the filter holds approximately 300lbs of sand.
3. Removing the old laterals takes a good grip to move the laterals out of there locked position to unlock them.
4. Cleaning the centre hub of all caked on sand and grime helps with the proper installation of the new laterals.
5. When replacing sand it’s critical to ensure that the laterals stay lateral and dumping the sand on top of them doesn’t help with that outcome. It is easy for a lateral to get dislodged during the refilling process.
6. Adding a bit of sand to the bottom of the filter first makes it easier to ensure the laterals stay in place when adding the remaining load of sand back into the filter.
7. I found by adding a small amount of sand back into the filter at a time and then adding water to level the sand down helped keep the laterals in place as I loaded back all 300 lbs of sand.
8. The job can be done but it is time consuming and needs a bit more precision to ensure success the first time.

That was my experience anyway. Thanks for the help as always TFP.

 

[Texas Splash]

I put a skimmer sock over the first jet and did not see any sand.

Great! Hope it stays that way.