Sand filter not filtering.

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
I have a sand dollar sand filter and it does not seem to be filtering properly. It is two years old and I have never done anything to it other than the normal backwash and rinse. I vacuumed the pool the other day and it was perfect, I went back out the very next day and all of the sand I vacuumed out seemed like it was back on the floor. It may not be all of it but most of it is. I saw in another post where it may be channeled and to hit the side of the filter with a rubber mallet but when I tried that dirt started coming out of the return. Any ideas what may be happening and what I should do? Thanks for your help.
 

JasonLion

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May 7, 2007
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Silver Spring, MD
Dirt coming out when you tap the filter with a mallet and having dirt come out confirms that the filter is channeled. You should follow the directions in this post to clean and resettle the sand bed inside the filter.
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
I will do that this weekend. It looks like I will have to cut the PVC pipe on each side of my valve on top of the filter, is there any way to avoid having to cut each time I have to do this?
 

JasonLion

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When you cut the pipes, install unions. Then the unions can be disconnected and the filter opened without any further cutting in the future.
 

JasonLion

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A flush union looks just like a regular union on the outside. The only difference is that you can push a piece of pipe all the way through it, there isn't any lip on the inside that stops the pipe when you are inserting it. If you can find flush unions they are easier to install because everything can stay in exactly the same position it was originally and you only need to cut each pipe once.

Installing regular unions can be done without too much work if you can't find flush unions. Places like Home Depot or Lowes aren't likely to have flush unions. To use regular unions you need to cut the pipe twice, so there is enough room for the width of the inner lip of the union.
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
Ok well I got my unions installed and removed the head of the filter. When I look inside at the sand I dont see any channeling or clumps of sand, its pretty dirty butI am flushing it out with a garden hose as we speak. When I look inside the filter what should I be seeing other than a stick of PVC and sand? Any ideas to why it would not be filtering as it should?
 

PaulR

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Jan 11, 2009
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Cupertino, CA
Channeling is not always visible, and clumps can be down where you can't see them. Put your hands right in and feel around for clumps, break them up if you find any. At the very least you'll be swishing the sand around and any channels will be broken up as it resettles.
--paulr
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
I stuck my hand in and did not feel any clumps so I got the hose with a nozzle on the end of it and stuck it down in the sand and moved it around until the water running out was clean.I dont know what else I can do. I had a hard time trying to get my hand further than 3 inches in the sand due to the pvc being in the way.
 

PaulR

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Jan 11, 2009
1,966
Cupertino, CA
Sounds like you've done what you can--the hose would have helped too--so put it all back together and see if there is any improvement.
--paulr
 

duraleigh

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Do you know for certain that it's dirt/sand and not dead algae? Can you post a set of test results?
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
I am certain its not algae, I have never had any type of algae in the pool. I guess I need to find some wood to knock on now.
FC=5
CC=0
ph=7.5
T/A=60 in process of raising to 70
CYA= 30

Thanks for the help. :-D
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
Well I went and bought all new sand last night for the filter. Cost me a whopping $28, I was suprised. Now the question is whats the easiest way to change it?
 

reindeerboy

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May 27, 2008
519
Jamestown, ND
If you have a shop vac, you can vacuum the old stuff all out. That would be the easiest. I did that and used a wheel barrow to haul it to the alley that is graveled and dumped it right in the alley. I also used it on a paver walkway to this alley.

Shop vac was quick, simple and fast. Then it gave me a chance to inspect the laterals and all the tubing as well. I would suggest that you replace your laterals since you are replacing the sand. I ordered mine online. It came in an assembly kit as I had the main tube broke as well so I bought the whole inner guts in one shot.

This is the second year running and the pool looks sweet. Take a look in my sig for pics!

I am sure some of the professionals will chime in soon.

good luck!
 

duraleigh

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After you get the sand changed and if it still leaks, make an inspection of the multiport valve. Since it's not algae, that's where I would look next.
 

jeremydu

Well-known member
Jun 24, 2008
77
MOBILE, AL
duraleigh said:
After you get the sand changed and if it still leaks, make an inspection of the multiport valve. Since it's not algae, that's where I would look next.
If it was the multiport valve how hard is that to fix? Is it expensive? I have a feeling that may be the problem since when I had the valve off everything looked good in the tank and of course I always have the best of luck :hammer:
 

duraleigh

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Most frequently, it involves replacing the "spider" gasket......should certainly be less than $20.00