Water seeping thru filter wall

jeharley

Well-known member
Mar 30, 2017
45
Lexington, SC
#1
Good morning, everyone.

I bought a house with a 30 year old pool. I have a sand filter that I've been told is also old and may need replacing. It seems to work fine so far although I have noticed that after running it for a few hours, one area.on the upper side of the filter starts to get wet... like water is slowly seeping through it. I need a new pressure gauge as mine reads 7 psi when off. I have just been subtracting 7 from whatever the reading is when it's on. After backwash it shows 17 so I assume it's actually 10. I've been running it close to 20 (13) for a couple days because of adding CYA and CH increaser.

Any advice on what this water seepage means? Is this normal or a major concern? Anything I can do to stop it?

20170412_090315.jpg 20170412_090315.jpg

- - - Updated - - -

accidentally posted twice... the dark spot is the wet area... it expands to about 3 times that size after running for 8 hours.
 

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
#2
Contrats on the new house/pool! I'm not a fiberglass expert, but I suspect the shell is simply worn from sun/oxidation and showing signs on wear. Not sure if you can re-coat it, or if that's the best choice with a filter that old. I suspect a total replacement at some point might just be your best option.

On a side note, not quite sure why you say the PSI is running a bit higher because of adding stabilizer and calcium. The elevated readings might be an indication of something else in the water. Just a thought. If you have a TF-100 or Taylor K-2006C test kit, you're welcome to post a full set of results and we can advise.

Welcome to yet another pool season. :swim:
 

JVTrain

TFP Expert
Feb 3, 2014
5,080
Central Minnesota
#3
What's your current pool water temp? What's the air temperature like? Humidity?

It could be just condensation from the cold pool water cooling the filter housing, then water from the air condensing on the cold surface.

The fiberglass does look fairly sun-weathered but I'm not sure the fiberglass would start allowing water through (become porous) unless it were badly damaged and thinned. If you don't think it's condensation from the water cooling the fiberglass surface + humid air, you could apply a thin layer of epoxy to the top of the filter to make sure it's seal and non-porous. Something like this: https://smile.amazon.com/3M-20122-Purpose-Fiberglass-Resin/dp/B003ODJ8J4/ref=sr_1_1?ie=UTF8&qid=1492029249&sr=8-1&keywords=fiberglass+resin
 
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jeharley

Well-known member
Mar 30, 2017
45
Lexington, SC
#4
Contrats on the new house/pool! I'm not a fiberglass expert, but I suspect the shell is simply worn from sun/oxidation and showing signs on wear. Not sure if you can re-coat it, or if that's the best choice with a filter that old. I suspect a total replacement at some point might just be your best option.

On a side note, not quite sure why you say the PSI is running a bit higher because of adding stabilizer and calcium. The elevated readings might be an indication of something else in the water. Just a thought. If you have a TF-100 or Taylor K-2006C test kit, you're welcome to post a full set of results and we can advise.

Welcome to yet another pool season. :swim:
Thanks for the response. The filter was running high because there was a lot of fine debris in the pool that I have been slowly brushing up and allowing the filter to clean out. That and the chalking paint being suspended in the water and adding a large amount of granulated chemicals... Makes sense that all of that could combine to cause more debris in the sand filter, plus the reason I mention CYA and CH increaser is bc I was trying to hold off on backwashing for a few days to let the chemicals take full effect.
 
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jeharley

Well-known member
Mar 30, 2017
45
Lexington, SC
#5
What's your current pool water temp? What's the air temperature like? Humidity?

It could be just condensation from the cold pool water cooling the filter housing, then water from the air condensing on the cold surface.

The fiberglass does look fairly sun-weathered but I'm not sure the fiberglass would start allowing water through (become porous) unless it were badly damaged and thinned. If you don't think it's condensation from the water cooling the fiberglass surface + humid air, you could apply a thin layer of epoxy to the top of the filter to make sure it's seal and non-porous. Something like this: https://smile.amazon.com/3M-20122-Purpose-Fiberglass-Resin/dp/B003ODJ8J4/ref=sr_1_1?ie=UTF8&qid=1492029249&sr=8-1&keywords=fiberglass+resin
The only reason that I am skeptical it is condensation is because it always occurs in the same isolated spot while the rest of the filter is bone dry... and the moisture seemed to be a bit milky after my pool water was milky and I ran the filter. Although, I got the pressure back down and yesterday the filter was dry by the end of running the pump... about 4 pm. The Temps around here right now are lows in the 50s and highs in the 80s. I do not check my pool temp but I would guess it is somewhere in the 60s.
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,398
Sebring, Florida
#6
Get a new filter. I think that filter body is worn out. If there is any dangerous part of a pool, it is that large, pressurized mass in the filter that could let go suddenly.

30 years is long enough. Everything I see in that picture indicates UV degradation (the sun) and I would replace it.
 
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jeharley

Well-known member
Mar 30, 2017
45
Lexington, SC
#7
Get a new filter. I think that filter body is worn out. If there is any dangerous part of a pool, it is that large, pressurized mass in the filter that could let go suddenly.

30 years is long enough. Everything I see in that picture indicates UV degradation (the sun) and I would replace it.
Thanks for the advice. I'm not sure if the filter is 30 years old, but the house is 30 years old and the pool seems to be about the same.

Is there any particular filter type that you would recommend for this set up? Where can I get the best prices for a new filter? Are they hard to install yourself?
 

duraleigh

Admin
Mod Squad
TFP Expert
Platinum Supporter
LifeTime Supporter
In The Industry
Apr 1, 2007
31,398
Sebring, Florida
#8
Other than (what I think is) the structural leak in your filter, have you been happy with it's operation? If so, get the same thing.

"hard to install" is relative. I would say don't do it unless you feel comfortable with it.
 

JVTrain

TFP Expert
Feb 3, 2014
5,080
Central Minnesota
#9
New filters are fairly easy to install. If you have any experience joining PVC pipe or are willing to do a little google searching to learn about cutting, gluing PVC it's very doable DIY. REALLY depends on your handy-ness and willing to accept that it's your responsibility to do it right.

The only problem you'll have is deciding what filter to replace it with! You could stick with a sand filter and look for one in a similar size. Based on your pool volume, I'd say something that has 200+ pounds of sand would be enough. Add the details of your pool pump (HP) for better advice on that. Make sure the filter will fit in the space of the old one. Pentair, Hayward and Jandy are typically the brands that I would feel comfortable recommending based on TFP users comments and generally will stand behind their products. I purchased my sand filter a few years ago off of Amazon but you can check other pool supply websites as well such as Swimming Pool Supplies - Pool Parts - INYOPools.com

In case you want to look at other types of filters and their advantages/disadvantages, check here: Pool School - Pool Filter Comparison
 

JVTrain

TFP Expert
Feb 3, 2014
5,080
Central Minnesota
#11
You would be happy with a direct replacement for the filter. It is likely either a Triton TR 40 or TR 50. You can tell by measuring the diameter of the housing. TR 40 = 19 inches, TR 50 = 21 inches. See the new models here: https://www.pentairpool.com/~/media/websites/pool/downloads/filters/brochures/triton_ii_fiberglass_sand_filter_english.pdf

See Triton at inyopools.com here: Pentair Sand Filters - INYOPools.com

Locally, you'd likely be able to get whatever model you chose for a Triton through Home | American Pools and Spas Inc