Sand filter not filtering out small particles

[HeidiJSmith]

16,000 gallons, plaster with fiberglass walls and attached fiberglass hot tub.
We bought the home in 2011, the pool had been covered and had not been used for five years. I found TroubleFreePools in 2012. Bought the test kit and balanced the water according to TroubleFreePool recommendations. The only parameter that’s on the higher end is CH, runs around 500. There is scaling. Installed a new Tagelus Pentair sand filter in 2013 and filled it with sand from the pool store. Everything was well until last year, when the filter started to pass small particles. When dried, it feels like ground up chalk. It makes the water cloudy.
Question: Should we open the filter and deep clean it? Put in more sand? Is there any way to fix this without opening the filter?
The filter is inside the home in the basement, so letting the water run over for deep cleaning is not feasible.
All the work is done by my husband who installed the whole setup back in 2013.

 

[RTamanda]

Yikes, pool equipment in your basement, bless your heart! Maybe try a good, long backwash? Like, fill your pool way high and backwash 30 minutes or so. Hopefully it would be enough to break up any channels. If that doesn’t work, open it up and give it a good stir (be careful not to damage the laterals!), then backwash and rinse. Hopefully one of the experts will come along soon and know exactly what your problem is, but those are things I would try!

 

[Texas Splash]

Heidi, welcome (officially) to TFP! Interesting that everything has been fine up until recently. So you had a trouble free pool for about 10-11 years right? Sand doesn't typically go bad, so unless a pool store gimmick product was added it should still be good. But if you did add something to the water in the past other than liquid chlorine, muriatic acid, baking soda, or stabilizer, let us know.

These chalky clumps, it doesn't sound like algae, but it would be good to see a full set of water test results to be sure since the water is cloudy. Have you tried collecting the clumpy material, placing it in a pile in the yard somewhere, and slowly pouring some muriatic acid on it? If it fizzles it's calcium related. If none of this helps, it may just be that the filter needs a deep cleaning after all these years, but I understand your concerns about the basement. In that case, you may have to remove some of the sand to allow you or your husband room to work with. With some sand removed, then push some water in there to slowly lift debris and break-up any compacted sand without overflowing the filter. A bit tricky, but I'm sure you can do it.

Deep Cleaning a Sand Filter

This post will walk you through the anatomy of a sand filter, and then provide a video at the end for how to deep clean your sand filter. The filter used in the photos and videos is a Hayward S180T top mount sand filter. The images are of a similar filter. Obviously not all filters are...

www.troublefreepool.com

 

[Texas Splash]

Also, don't forget to update your signature. The link below should help.

Create Your Signature - Further Reading

www.troublefreepool.com

 

[Texas Splash]

One final thought. Let's say your chemical balancing is "TFP perfect". To be safe you also conduct an Overnight Chlorine Loss Test. Then you stir up the sand and confirm it's not compacted or any junk in there. If these particles don't seem to be related to anything else you can confirm, you might just try adding a little DE to the filter for a few days to see if that helps the filter collect this stuff so you can backwash it. The link below explains adding DE to sand. But I would use the DE as a last resort.

Add DE to a Sand Filter

A clean pool filter will increase the efficiency of your pool! ... your filter are to backwash it, clean the manifolds and grids, and add new DE.

www.troublefreepool.com

 

[Newdude]

Just for theory sake, if you have valves on the equipment to stop the pool water flow, you can drain the filter into buckets and shop vac the sand out. While we usually advise that cleaning the sand is good enough, it's probably worth the less mess for you to just replace it. Then you'll know it's fine indefinitely, free of anything that would gum it up.

If you don't have valves, then plug the pool openings with rubber stoppers and drain the plumbing along with the filter with several bucket trips outside.

 

[1poolman1]

16,000 gallons, plaster with fiberglass walls and attached fiberglass hot tub.
We bought the home in 2011, the pool had been covered and had not been used for five years. I found TroubleFreePools in 2012. Bought the test kit and balanced the water according to TroubleFreePool recommendations. The only parameter that’s on the higher end is CH, runs around 500. There is scaling. Installed a new Tagelus Pentair sand filter in 2013 and filled it with sand from the pool store. Everything was well until last year, when the filter started to pass small particles. When dried, it feels like ground up chalk. It makes the water cloudy.
Question: Should we open the filter and deep clean it? Put in more sand? Is there any way to fix this without opening the filter?
The filter is inside the home in the basement, so letting the water run over for deep cleaning is not feasible.
All the work is done by my husband who installed the whole setup back in 2013.

After 11 years, it is very likely that you need to add at least 50# of sand to the filter. The only way to do that is to lift the valve off the top, sorry. Be sure that any valves that stop water from running back to the equipment are closed and you should be fine.