I have an in ground pool with a Hayward S-220T sand filter. Last summer I noticed sand coming in the pool from the return lines. The amount wasn’t huge and it was toward the end of the swimming season so I didn’t do anything at the time. When I opened the pool a few weeks ago I had emptied the sand, changed the entire stand pipe, previous one did have a smalll crack at the bottom of the base where the laterals connected. The new lateral insert I installed was the correct Hayward Part #. I followed the refill instructions, filled half full of water, covered the top of the stand pipe, put the lateral and pipe piece in and added the sand. When I kicked the system on I was still getting sand. I then bought a new multiport valve, hooked it all back up, still sand. I backwashed for a couple min to get the water clear in the glass, rinsed for a good minute, maybe two, same thing more sand. I’ve been running it just on recirculate for past 2 days thinking if the pool is sand free then I know it’s the filter, but I’m getting sand even with the just recirculating. Any suggestions? I would think if I had an issue with a leak in the return line the water under pressure would leak out and I wouldn’t get sand (return line runs pretty shallow under pavers sand) coming into a leaking line. I’m stumped. Thanks for any suggestions!
Sand in the pool after new standpipe and new multiport valve
- Thread starter BTDinROC
- Start date
- Jun 22, 2014
- 48,268
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Welcome to TFP! 
if you are getting sand in the pool while on recirculate, with a new MPV, it's not the filter. Things that come to mind are:
- Is it actually sand? Does it feel gritty?
- What brand of sand did you get? Some brand are not good.
if you are getting sand in the pool while on recirculate, with a new MPV, it's not the filter. Things that come to mind are:- Is it actually sand? Does it feel gritty?
- What brand of sand did you get? Some brand are not good.
Sorry for the long period to reply here are some pictures of the sand I bought, in the pool and after I vacuumed with pantyhose to catch the sand, it is gritty and after I vacuumed again this weekend I did another thorough back wash and rinse for another 90 seconds or so, still getting similar debris field underneath the rerun line 
Attachments
- Jun 22, 2014
- 48,268
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Could you post some pics of your equipment pad too please? We'd like to see the filter connections, plumbing lines, etc. Might give us more to go on since you basically changed everything in/on the filter already.
Sure here it is, just have a chlorine feeder attached besides the filter and pump. I’m almost inclined to take it all apart and start over again to see if there’s some issue I created putting it back together last time (was my first time doing any of those those things), as far as the sand when recirculating I’m wondering if I had some sand in the pump filter basket area left from my initial vacuum that made its way back when I did the recirculate cycle. I’m back to filtration mode now and have a small debris pile underneath the returns again 
- Jun 22, 2014
- 48,268
- Pool Size
- 17888
- Surface
- Fiberglass
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Thanks for the pic. That is the same pump as before correct? I'm not seeing any obvious red flags that would explain sand entering the pool. Since it also happens in recirculate, that would suggest there was residual sand somewhere as you noted (i..e in the pump pot) or it got pulled into the pool from somewhere else. But you aren't experiencing any water loss to suggest a plumbing leak are you? Even if you were it would mean you had sand in the ground.
While in filter mode, the only way sand could somehow get from the filter to the pool is if the laterals/center pipe had a problem (which you just replaced), some of the sand grains are too small, the MPV spider gasket or key diverter was somehow installed incorrectly at the factory or defective (doubtful), thereby allowing water to pass to/from the filter while in recirculate. MYSTIC WHITE II filter sand has been known to produce three effective sizes, .49 mm, .65 mm or .80 mm. Perhaps the bags you purchased have the smaller sizes and that's what you are seeing slip through the lateral slots?
In addition, if you added too much sand this spring, I suppose it's possible the extra is getting blown out of the filter and perhaps getting back into the plumbing. I'd hate to see you go back into the filter after all the work, but if this continues, you may have to back-track everything to be sure.
If I was placing bets in Vegas, I'd go with:
1 - Batch of sand has too many small grains
2 - Too much sand added
3 - Problem with the spring repair (lateral/center pipe)
While in filter mode, the only way sand could somehow get from the filter to the pool is if the laterals/center pipe had a problem (which you just replaced), some of the sand grains are too small, the MPV spider gasket or key diverter was somehow installed incorrectly at the factory or defective (doubtful), thereby allowing water to pass to/from the filter while in recirculate. MYSTIC WHITE II filter sand has been known to produce three effective sizes, .49 mm, .65 mm or .80 mm. Perhaps the bags you purchased have the smaller sizes and that's what you are seeing slip through the lateral slots?
In addition, if you added too much sand this spring, I suppose it's possible the extra is getting blown out of the filter and perhaps getting back into the plumbing. I'd hate to see you go back into the filter after all the work, but if this continues, you may have to back-track everything to be sure.
If I was placing bets in Vegas, I'd go with:
1 - Batch of sand has too many small grains
2 - Too much sand added
3 - Problem with the spring repair (lateral/center pipe)
Sorry don’t know how that reposted again, thanks so much for your help, I’ll keep tinkering.
