Sand in pool with NEW Filter

[damhayes]

Hello all, I might have a good one that I hope someone can help me with. Last season I starting to get sand in my 12’x24’ inground pool. I am using a Hayward S160T sand filter with a Hayward 3/4hp pump. I 1st replaced the laterals, added new sand, still have sand in pool. Then I replaced the spider gasket, still have sand in the pool. Then my local pool store let me try a whole new Hayward VariFlo Top-Mount Multiport Valve, installed it, still have sand in the pool. They suggested a new filter. This season, after opening pool I replaced my filter with a Hayward W3S166T with new valve, new sand, etc. I then proceed to backwashed, then run filter and I still have sand in pool. Sorry so long, so I put the filter on recirculation to bypass filter, still sand in pool. There is no sand that I can see in the pump filter strainer. I am still using the same 3/4hp pump. I hope someone out there can help me; I am at a total loss. Thank you so much for your time and help.
Derek

Photos of sand in pool, filter and sand used.

 

[Texas Splash]

Hello and welcome to TFP! Silly question but ...... are you 100% sure what you are seeing is sand? Sand should definitely feel gritty. I'm looking at one of your pics and it looks like green algae across the floor. Can you clarify for us?

 

[damhayes]

Hello and welcome to TFP! Silly question but ...... are you 100% sure what you are seeing is sand? Sand should definitely feel gritty. I'm looking at one of your pics and it looks like green algae across the floor. Can you clarify for us?

Thank you for the question, oh it is sand. I use a hot tub vacuum (battery operated) and when I empty it, it's all sand.

 

[1poolman1]

Hello all, I might have a good one that I hope someone can help me with. Last season I starting to get sand in my 12’x24’ inground pool. I am using a Hayward S160T sand filter with a Hayward 3/4hp pump. I 1st replaced the laterals, added new sand, still have sand in pool. Then I replaced the spider gasket, still have sand in the pool. Then my local pool store let me try a whole new Hayward VariFlo Top-Mount Multiport Valve, installed it, still have sand in the pool. They suggested a new filter. This season, after opening pool I replaced my filter with a Hayward W3S166T with new valve, new sand, etc. I then proceed to backwashed, then run filter and I still have sand in pool. Sorry so long, so I put the filter on recirculation to bypass filter, still sand in pool. There is no sand that I can see in the pump filter strainer. I am still using the same 3/4hp pump. I hope someone out there can help me; I am at a total loss. Thank you so much for your time and help.
Derek

Photos of sand in pool, filter and sand used. View attachment 586259View attachment 586262View attachment 586258View attachment 586260

Are you seeing sand come from a return line? That doesn't look like sand but it does look like dirt that has settled. When the valve is in the "recirc" position the water doesn't even go through the filter but just into the valve and back to the pool. What else is in your area? A lot of trees, fields, etc.? Mystic White II sand is very light colored and that debris is very dark.

 

[damhayes]

Thanks for the response. I am going to put a panty hose on the return line tomorrow morning and see. The pool has a 4 foot apron, then grass after that. I do have some big maple and oak tress that are near me but on state land. Thanks

 

[damhayes]

So, the other day I went without running the filter to see if any outside debris is coming in, pool is sand free. The next day I put a panty hose over the return line, (nice and snug wrap around the return jet) ran filter and notice sand in the pool but not as much, but no sand in the panty hose, huh. Could it be the sand being too fine? Still at a loss. Thank you for any help you can provide.

 

[Texas Splash]

Could it be the sand being too fine?

Perhaps, although I've not heard of many complaints about the Mystic White brand. But now I would like to clarify something because above in Post #1 you noted that sand was still in the pool when on recirculate which is odd because water isn't touching the inside of the filter at that point. Here in your last post (#6) you stated no sand when you went "without running the filter". So basically system totally off - no water movement at all?

 

[damhayes]

Yes, no water movement at all, system was turned off, no filter running. I know this sounds strange. Thank you again.

 

[Texas Splash]

sand in the pool but not as much, but no sand in the panty hose, huh. Could it be the sand being too fine?

Got it. So now we have to figure out how sand (if that's what it is) could get past a nylon and into the pool. If it were one my my socks we would know immediately - holes. ha ha. Above you said you were sure it is sand (from your hot tub electric vacuum). So it is definitely gritty right? No other such similar substance around the pool area? In Post #1 you confirmed you have inspected and/or exchanged just about everything filter related. Between all that work & expense, plus not catching any in a nylon, it doesn't make any sense how sand could be getting in the water from your filter. Maybe at first following some new backwash and rinse modes, but that should all settle down. Any odd weather (windy) that might have blown this stuff into the pool?

Sounds like you've been doing this for a while, but just to ask, you haven't had any concerns about backwash and rinse techniques have you?

 

[damhayes]

Ha, I wish it was hole in the sock. Yes the sand is gritty. The weather has been a heat wave, no wind just hot. Never had any issues with the backwashing but maybe a different technique or longer backwashing? I have attached some new pictures from today to show the sand. The sand is lighter than it looks in the pictures. Thank you all for helping me.

 

[Texas Splash]

It's odd that sand seems to make it to the pool but not caught in the nylon. I mentioned the backwashing only in case perhaps you needed to do the rinse a bit longer. Once the waste line or sight glass goes clear, some people will rinse an additional 30 seconds or so just to be sure.

 

[damhayes]

I'll give it a try tomorrow. Can't hurt, thank you again.

 

[Lake Placid]

Your initial pics look like dead algae on the floor, however the gritty texture would indicate otherwise. Have you used any DE in the filter to assist filtration? If not, I’d perform an OCLT and if comes back good, then assume your issue is environmental debris.

 

[Mayorb]

Sand escaping from filter to the pool pretty much always makes a "sand drift" right below the returns and nowhere else.
It's too heavy to get very far from those. Maybe very small debris (pollen, etc.) blowing right through the filter?

 

[damhayes]

I have never use DE for my filter. I attached some pictures of the sand that I vacuum out of the pool. Thanks again

 

[Texas Splash]

Are you still confirming that the sand appears on the pool floor, but doesn't seem to get caught by a nylon at the return jets?

 

[damhayes]

Yes, nothing in the nylon sock. Just doesn't make sense. Thanks

 

[Texas Splash]

nothing in the nylon sock. Just doesn't make sense. Thanks

Okay then. Well, if that nylon is fine enough to catch sand and you're not seeing any in it spurt out from the jets, then it must be coming from outside the pool. There's just no other way for sand to get in the pool from the filter. Quite the mystery for sure. One day I suspect you'll have one of those "Ah- ha!" moments and crack the code on where that stuff is coming from.

 

[damhayes]

I know, it's quite the mystery. I hope I do find the issue, I am losing it. Had the pool for 27 years and the last two are driving me crazy. If anyone else can think of anything I'll check back regularly. Thank you all for the help.