Help with a sand filter

nbasile

Member
Aug 31, 2021
10
Connecticut
I've been having an ongoing issue with my sand filter this season. It started off small but came to a head last week. This is a 15' round, above-ground pool.

Since the start of the season I was getting little bits of sand in my pool. It didn't really bother me that much because I have a good battery operated vacuum and they were relatively small amounts anyways. But recently my pool started getting cloudy. I assumed my chemistry was a bit off, which would have a surprise since I have it checked weekly at the Leslie's down the street and it was almost always perfect. Sure enough, when it was cloudy, it was still perfect.

Well now my pool is straight up green. The store manager determined it must be a filter issue. This sand is only one year old so I assumed I had a broken lateral or standpipe. I emptied the filter and hosed everything down but nothing on the inside is visibly broken. Now I'm wary of putting this back together only to find out that I missed something. Is there a way to actively test these laterals to make sure they are in working order? Also, what else could have possibly caused this issue if the pipe and the laterals are working? There was a brief time earlier in June where I know my sand filter wasn't completely level but could that have had that effect on my pool now, two months later?

The guy that did my pool install also filled the sand filter so I can't guarantee that he used the correct sand but it looks visibly similar to the sand I bought today, which is #20 silica.
 

YippeeSkippy

Mod Squad
LifeTime Supporter
Jan 17, 2012
17,551
Evans, Georgia
Dear Nbasile....your pool is green because you listen to a pool store and get your water tested there. They rarely have a clue, as evidenced by your green pool with "perfect" chemistry.

Algae is a chemistry problem, not a mechanical one. Your pool didn't have enough Free Chlorine (FC) in the water balanced against your CYA stabilizer level.

First off- you need your *own* test kit and it must have the FAS-DPD tester in there for both Free Chlorine (FC) and Combined Chloramines (CC) at a higher level than a pool store usually tests for.

My preferred TFP approved kit is the TF-100 available at www.tftestkits.net or you can buy an K-2006C test kit on Amazon. Don't buy the K-2006 (without the C because you'll run out of reagents too fast). The TF-100 is cheaper anyway.

I don't know a way to "test" the laterals other than a visual check, but you could have the wrong sand in there for sure.

Can you please go to <Settings> and <Signature> and fill out details about your pool, its equipment, how you chlorinate, the size, ect. This helps us answer you better without a lot of extra questions.

Maddie :flower:
 
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wireform

Silver Supporter
In The Industry
Aug 15, 2017
2,999
Spring Valley, NY
He said it's a filter issue. For that alone should serve as a deterrent not to step into pool stores period. Not a clue he has but he's got to be right after all he works at Leslie's. As Maddie said it, You simply need your own testing.
 
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nbasile

Member
Aug 31, 2021
10
Connecticut
Dear Nbasile....your pool is green because you listen to a pool store and get your water tested there. They rarely have a clue, as evidenced by your green pool with "perfect" chemistry.

Algae is a chemistry problem, not a mechanical one. Your pool didn't have enough Free Chlorine (FC) in the water balanced against your CYA stabilizer level.

First off- you need your *own* test kit and it must have the FAS-DPD tester in there for both Free Chlorine (FC) and Combined Chloramines (CC) at a higher level than a pool store usually tests for.

My preferred TFP approved kit is the TF-100 available at www.tftestkits.net or you can buy an K-2006C test kit on Amazon. Don't buy the K-2006 (without the C because you'll run out of reagents too fast). The TF-100 is cheaper anyway.

I don't know a way to "test" the laterals other than a visual check, but you could have the wrong sand in there for sure.

Can you please go to <Settings> and <Signature> and fill out details about your pool, its equipment, how you chlorinate, the size, ect. This helps us answer you better without a lot of extra questions.

Maddie :flower:

Thanks. I will look into my own testing. Until that arrives, what do you think would be the appropriate action after putting my filter back together?
 
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ferretbone

In The Industry
May 24, 2016
147
tx
Water balance, circulation, and filtration. Your missing one or more.
I'm taking everything at face value from you and the pool store. Well not really, 1st the filter.

Check for an little tube sticking high up. Make sure its not veke or pulled out. Those tiny sand filters spit stuff back after back washing but sand should not spit back. Put it in backwash withthe lid off and turn on the pump. The water should fill from the bottom, anything spraying from the top should have a hose or screen on it. Kill the power.
Now check each lateral on buy one. un thread them and pull them out to check for splits. If they are good and you have a air hose to the top of the fitler and some kind of screen on that hose get your new sand.
If you got all the old sand out of the filter fill it back up with the new sand about 3/4 full. And run your pool 24/7 backwashing once a day while waiting for your kit.

Now I, and ferretbone means I alone would shock the water after. Not add Chlorine, but shock it while leaving that pump running. Shocking is an action, you do the math
Let us know how the filter looks.
 

nbasile

Member
Aug 31, 2021
10
Connecticut
Water balance, circulation, and filtration. Your missing one or more.
I'm taking everything at face value from you and the pool store. Well not really, 1st the filter.

Check for an little tube sticking high up. Make sure its not veke or pulled out. Those tiny sand filters spit stuff back after back washing but sand should not spit back. Put it in backwash withthe lid off and turn on the pump. The water should fill from the bottom, anything spraying from the top should have a hose or screen on it. Kill the power.
Now check each lateral on buy one. un thread them and pull them out to check for splits. If they are good and you have a air hose to the top of the fitler and some kind of screen on that hose get your new sand.
If you got all the old sand out of the filter fill it back up with the new sand about 3/4 full. And run your pool 24/7 backwashing once a day while waiting for your kit.

Now I, and ferretbone means I alone would shock the water after. Not add Chlorine, but shock it while leaving that pump running. Shocking is an action, you do the math
Let us know how the filter looks.

I've already completely discarded the old sand, purchased new sand, and washed the inside of the filter. At this point, I'm mostly wondering if the laterals are damaged. They seem visibly fine, but there was some sand in them and some sand at the base of the standpipe. I did have some difficulty with positioning my sand filter at the start of the season, which I'm wondering if that is the culprit for the sand in my pool
 

ferretbone

In The Industry
May 24, 2016
147
tx
I've already completely discarded the old sand, purchased new sand, and washed the inside of the filter. At this point, I'm mostly wondering if the laterals are damaged. They seem visibly fine, but there was some sand in them and some sand at the base of the standpipe. I did have some difficulty with positioning my sand filter at the start of the season, which I'm wondering if that is the culprit for the sand in my pool
Did you vacuum the sand in your pool while in backwash? Sound like it.

Sorry I just asummed you had a Front port multi not a top mount. My bad I just figured that out.

"positioning my sand filter at the"
Is it seating tilted? Like really tilted? The bottom of that multiport would have to be getting sand into it durning backwash, thats hard to do. So that doesnt sound like an issue. Get the sand out of the laterals and sandpipe. That sand got in there from vacuuming the pool in backwash, or there is a broke lateral, a cracked laterals hub etc.
 

nbasile

Member
Aug 31, 2021
10
Connecticut
Did you vacuum the sand in your pool while in backwash? Sound like it.

Sorry I just asummed you had a Front port multi not a top mount. My bad I just figured that out.

"positioning my sand filter at the"
Is it seating tilted? Like really tilted? The bottom of that multiport would have to be getting sand into it durning backwash, thats hard to do. So that doesnt sound like an issue. Get the sand out of the laterals and sandpipe. That sand got in there from vacuuming the pool in backwash, or there is a broke lateral, a cracked laterals hub etc.

It's kind of difficult to explain but yes, it was tilted on the seat. And yes, it was fairly tilted. I was stretched thin on hoses and cables, but that issue has since been fixed. My vacuum is independent of the pool itself so it isn't that. I have all the laterals in front of me and nothing looks broken that I can tell.
 

ferretbone

In The Industry
May 24, 2016
147
tx
Sorry for the double post but whoever fill the filter with sand the last time could have spilled some into the sand pipe trapping it there. The botton hub holding the lateral spins off. Pull out out and double check it for cracks while checking those laterals. If those are good then there was some kind of human error in the past to get sand inside the laterals.
 

nbasile

Member
Aug 31, 2021
10
Connecticut
Sorry for the double post but whoever fill the filter with sand the last time could have spilled some into the sand pipe trapping it there. The botton hub holding the lateral spins off. Pull out out and double check it for cracks while checking those laterals. If those are good then there was some kind of human error in the past to get sand inside the laterals.

Thanks man. The guy that did my install definitely was struggling with the filter at one point so its possible he screwed that up. I'll double check the pipe but I feel like if the laterals and pipe were broken, it would be immediately noticeable, right?
 

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JamesW

TFP Expert
Mar 2, 2011
27,782
Do you have a picture of the filter and the plumbing?

Does the line from the pump go to the top port of the multiport?
 
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ferretbone

In The Industry
May 24, 2016
147
tx
Where does your air relief go into or out of for your filter? That part on the top out side of the multiport where you let air out? Is there no hose under it inside the filter? Thats the last thing that can bring sand into the laterals. You have real filter sand, so check that off the list. The laterals are not broke check. The sand didn't come from the pool while being vaccumed. Even if you were trying to get sand sucked into the bottom of the multiport on purpose by tilting it to much would prove be very tough.

So that leaves, the sand was poured into the sandpipe on the last sand change or fill. And blow out little at a time, prolly after backwashing.
An air relief tube or screen is missing inside the filter.
Or you have a deceiving crack in something plastic like that black rd hub the laterals are screwed into. Maybe cracked and you cant see it without removing it. Or pushing and pulling on the seems.
 

shwn2405

Well-known member
Jun 7, 2021
52
Terre Haute, IN.
Pool Size
17200
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
Sounds like human error with your sand filter. You need to fill out your signature too as well. Just helps us know your pool and what you're working with. A cloudy pool means you have algae, has nothing to do with filtration. We never give advice on pool store testing because they are always wrong and why you have a cloudy pool. To permanently kill and remove algae, you need follow our SLAM Process page, but you need to purchase a TF-100 or Taylor K-2006C test kit RIGHT NOW👍 to test and maintain the proper SLAM-elevated free chlorine level required as noted on the FC/CYA Chart.
 

nbasile

Member
Aug 31, 2021
10
Connecticut
Sounds like human error with your sand filter. You need to fill out your signature too as well. Just helps us know your pool and what you're working with. A cloudy pool means you have algae, has nothing to do with filtration. We never give advice on pool store testing because they are always wrong and why you have a cloudy pool. To permanently kill and remove algae, you need follow our SLAM Process page, but you need to purchase a TF-100 or Taylor K-2006C test kit RIGHT NOW👍 to test and maintain the proper SLAM-elevated free chlorine level required as noted on the FC/CYA Chart.

Thanks man. Already ordered the kit when Maddie recommended it. Hopefully here before the end of the week. I'll take a look at that SLAM process page.
 

nbasile

Member
Aug 31, 2021
10
Connecticut
Do you have a picture of the filter and the plumbing?

Does the line from the pump go to the top port of the multiport?

It's this one.


It's pretty dark so I can't get a picture of my personal pool atm.
 
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nbasile

Member
Aug 31, 2021
10
Connecticut
Where does your air relief go into or out of for your filter? That part on the top out side of the multiport where you let air out? Is there no hose under it inside the filter? Thats the last thing that can bring sand into the laterals. You have real filter sand, so check that off the list. The laterals are not broke check. The sand didn't come from the pool while being vaccumed. Even if you were trying to get sand sucked into the bottom of the multiport on purpose by tilting it to much would prove be very tough.

So that leaves, the sand was poured into the sandpipe on the last sand change or fill. And blow out little at a time, prolly after backwashing.
An air relief tube or screen is missing inside the filter.
Or you have a deceiving crack in something plastic like that black rd hub the laterals are screwed into. Maybe cracked and you cant see it without removing it. Or pushing and pulling on the seems.

Sorry, pretty new to this so I'm not exactly sure what I should be looking for there. The inside of the filter (besides sand and water) was just the standpipe and laterals The pipe fits into the multi-port valve. IIRC, there seems to be some kind of vent there.
 

shwn2405

Well-known member
Jun 7, 2021
52
Terre Haute, IN.
Pool Size
17200
Surface
Vinyl
Chlorine
Salt Water Generator
SWG Type
Hayward Aqua Rite (T-9)
Great to hear @nbasile , stick with this community. They will help you through any problem👌! Read up on pool school and the forums! Tons of great info! Once you get that filter back up and running. Add 5ppm of sodium hypochlorite (aka bleach) which can be purchased at any Walmart or hardware store etc ..... Then wait for your test kit and give us your numbers.
 
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