Dumb questions about sand filter deep cleaning

[Bill in Bay Area]

I am a homeowner who tries to do as much pool care as I can without getting in over my head. My pool water is very clear, despite certain issues with chemistry and equipment.

My latest concern is that my sand filter is letting sand through; I get about a half cup of sand a day in the Polaris bag. It is at Pentair TA60D, 6 years old, and has never been deep cleaned. I backwash once a month, because the pressure gauge stopped working so I can't tell based on a pressure increase if it's time.

So I re-read everything in TFP about deep cleaning sand filters. It seems like the next step. But I have several dumb questions right off the bat.
1) How do I get at it? Do I have to cut the PVC and replumb when done?
2) How do I remove the multiport safely? There are many warnings about pressure and it being dangerous to remove the top.
3) I assume it is way to heavy to move, so I have to do it where installed, despite the videos showing a filter standing alone.
4) We have VERY high calcium in our water supply. Would the chemical wash be necessary?

Pool chemistry for reference:
FC 7ppm
pH 7.8
TA 190 (trying to lower this, but it never seems to get below 140 no matter how many times I lower pH to 7.0 and aerate)
Calcium hardness over 800
CYA 100 (trying to get this back down to 80, but it's very difficult. With the water restrictions I hate to drain enough waste water to accomplish this)
TDS 2600
Salinity 3100

Again, pool water is visibly quite clear and there is no scale visible on the outside surfaces. Not sure about the inside. I cleaned the SWG in June, and it was only moderately dirty before I did so. I AM getting white particulate flakes that settle below the 2 return jets; I assume that is calcium and perhaps indicates scale on the inside of the other pool machinery.

Sorry to be the noob. I'm torn between the desire to get it all fixed by calling in the pro and the desire to be self-reliant.

Cheers,
Bill

 

[Flying Tivo]

1) How do I get at it? Do I have to cut the PVC and replumb when done?

Do you have a picture? There should be unions, if not it will be a good time to do it.

2) How do I remove the multiport safely? There are many warnings about pressure and it being dangerous to remove the top.

Everything has to be done with the Pump Off and the breaker in the off position.

2) How do I remove the multiport safely? There are many warnings about pressure and it being dangerous to remove the top.No n

No danger if the pump is off, if you post a picture there is a clamp on the bottom of the MPV.

3) I assume it is way to heavy to move, so I have to do it where installed, despite the videos showing a filter standing alone.

No need to move, but finding sand in the pool is most likely due to a broken lateral. Which means you will have to empty the sand a deep cleaning will not help. You can use a wet shopvac to remove sand.

4) We have VERY high calcium in our water supply. Would the chemical wash be necessary?

What is your CH and TA fill water?? What test kit are you using?

 

[Bill in Bay Area]

Thanks for the reply, Tivo. Picture attached. No unions. It's always bugged me that the installer put it in with the gauge facing the back corner, so this is probably an excuse to get the plumbing reworked to orient it more conveniently and put unions on.

One the sand is removed, is replacing the lateral easy enough? What if it's not obvious which lateral is broken? Also, I'm curious how a lateral could break. Seems like they can't move when packed by the sand. I've never had it open since install, so it couldn't have gotten jarred by a deep cleaning. And the sand in the pool is a new thing this summer.

I've never tested the fill water. The pool shop I use for supplies says it's super high in this area (Santa Clara County) and there's nothing I can do about it, and I just took his word for it. I use the Taylor K-2006. Except I use a digital meter for pH because I have no confidence in the titrating kit; the colors never match for me, possibly due to running a high FC level. I also got the CY reading of 100 from having the shop test the water. My own reading is 80, but it is REALLY hard for me to tell just exactly when that black dot disappears, and I assume he's better at it than me.

 

[duraleigh]

And the sand in the pool is a new thing this summer.

That could be how a lateral was broken. Believing the pool store instead of yourself is not a good thing. We trust your results over a pool store........you care more. How old is that K-2006? Post complete test results and we'll bhe better able to help you.

 

[Bill in Bay Area]

I overestimated how much sand I'm finding in the Polaris bag. Probably under a quarter-cup.

The TAYLOR K-2006 is 6 years old. But the R-0870, R-0871, and R-0013 are newer "refills."

Test results taken just now using my Taylor kit, and the digital pH meter:
Fill water: CH 150, TA 100, pH 7.18
Pool water: CH 500, TA 170, pH 7.2, FC 3.5, CY 80, salinity 3100
(pH is typically 7.8, but I am in the middle of aerating to lower TA, so pH is a snapshot on the way up from 7.0)

So yes, I'm getting different results than from the test sample at the pool shop, especially for CH, TA, and CY.

Thanks

 

[Flying Tivo]

500 CH is still manageable, but dont use anymore powder chlorine, which is the reason its high since your fill ch is only 150. Also the TA was elevated manually. So stop adding anything that is not Liquid chlorine, muriatic acid or CYA if needed. Make sure you have the PoolMath app so you can track CSI and prevent scaling. Make sure you check the rest of your reagents for dates. I would rather start with fresh reagents all around.