CH Increasing + White Spots on Plaster

I decided to do a little science experiment. I swept up some of the dust and grit from the stone coping and added a bit of muriatic acid. It bubbled. I’m not sure that my experiment is conclusive, but I take it to mean that it’s likely there is at least some limestone dust in the stuff that gathers near the pool.

So maybe it is the dust that’s contributing to my high CH? Does that seem like a reasonable possibility?

New member, OLD pool, filters are rotting out, need advice on new filters

You must have missed that he is in Arkansas. :whistle:

Strange substance in vacuum basket

OK, I finally have some more information. I have had company for a week now with more on the way, plus my pump sprung a leak, so I've been busy, to say the least.

I cleaned the pool again and collected more white stuff. The image shows the powder with and without vinegar after they both dried. The sample on the right got soaked with vinegar. When they dried out, they looked exactly the same as the photo shows. However, the video shows the vinegar mixture bubbling for a short time. I also added a photo of my modest water test kit, which is within the margin of error of the readings I got from Leslie's, which I posted above. However, I don't have a CYA home test kit. Here is a link to the video of the vinegar test. Remember that the sample also had detritus from the bottom of the pool mixed in, and the vinegar may have been reacting to some biological material.

Thank you agaon for your responses.

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My test kit pieced together from various sources.
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This was also found in the vacuum. I have no idea what this could be.
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Sand in pool after changing laterals/standpipe

When opening the pool this Spring, and starting the pump... lots of sand in the pool. Eventually replaced the laterals (only 3 yrs. old) and replaced the Hayward, Vari-flo XL, key seal assembly (only 2 yrs old). Neither showed any problems with leaks, cracks or wear. After installing the new lateral unit I put in the same name brand sand I've always used. But it does not specify grain size. Still had sand coming in. I re-inspected the connection between the valve (bottom pipe) and the lateral stand pipe. It was not what you would call snug. The valve pipe has 4 slits at its opening to form somewhat of a "flare" to slip over the stand pipe. I used a tie-wrap around it and tightened the zip tie until I had a more snug fit. This seemed to help. But I'm still seeing sand coming in. Looking for any advice.

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New member, OLD pool, filters are rotting out, need advice on new filters

From the little research I've done we need to turn the water over 3 times a day
I would do more research, and understand the EXACT requirements that you need to meet. Including any sort of permitting, inspection and approvals you need. Then design the system around the requirements. This will avoid costly mistakes.

CH Increasing + White Spots on Plaster

The few white spots in your photos are NOT the same as what I wrote about in my article "White Spotting." Nor are they "calcium nodules." They are a minor plastering defect, which means they are not caused by unbalanced pool water, whether it be aggressive water or scale forming water. If there are only a few spots like that, then I won't worry much about them. Just unfortunate that they occurred and are there. And I doubt that those few spots would be the cause of the notable calcium increase.

You have grasped and understood the information provided to you very well.

Thanks for the info! That does make me feel much better!

There are only a few little spots like that. I see 6-8 total, plus maybe some really tiny ones I can see from the pool deck that could be either a “spot” or just a larger chunk of white aggregate. Visually, they’re really not very noticeable, and if they’re a plastering defect, then I guess it’s possible they’ve been there all along and I just never noticed. I admit, I’m looking much more closely at the plaster job now that I probably ever have.

In addition to the small, very bright white spots, there are a couple others that are more mottled looking and do bug me visually because they are larger. The two in the photo are about 1” in diameter. The one toward the bottom of the pic is definitely a depression in the plaster, and the other one feels the same as the surrounding surface. Do these appear to be defects and/or normal color variations/mottling?

I am still completely at a loss to explain the high CH levels. I really don’t think my fill water is the culprit. Even before now, I had measured the CH of the fill water from time to time, and it was always soft. And in the past couple days, I’ve measured it at various times of the day and after varying water demand from the house, and it’s always CH 0.

The only thing I can possibly think of is that some limestone dust from the coping is falling into the pool and dissolving, but I’m not even totally sure whether any of the coping is limestone. The orangey rocks could be, but I don’t know for sure.

I will do a partial drain & refill. Is a CH target of 800 reasonable? That would be about 1/3 of the water being exchanged and assumes no softened water being added to the pool.

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DIY valve automation for cooling pool

My AGP gets uncomfortably hot in July/August here in North Carolina. I want to use PVC pipe to create a sprayer/fountain to lower the pool temperature but I only want to run it for a few hours in the middle of the night. I do not have pool automation. I was thinking about teeing off of my return line into an actuated valve ( maybe a sprinkler valve) connected to some type of timer. Has anyone done anything like this, or have any suggestions?

Questions about free chlorine

free chlorine at 13 is okay since it seems so high
Absolutely. Do it now.

Read this article:

How did you get 120? How are you testing your water. I would recommend that you retest starting at #8 here:

Questions about free chlorine

@stacy78132,
can you post your latest results so we can ensure things are going swimmingly?
Fc
Cc
Ph
Ta
Ch
Cya
Salt (if applicable)
I attached a screenshot with my numbers from yesterday. Yesterday I was told to add 1 gal and 3 cups of 10% liquid chlorine so I added that last night. Since it's was the 1st time I used liquid I t3sted only the chlorine and pH today. Free chlorine was 5 and combined chlorine was 0. My pH was 7.8. Yes cya is around 125...it was much higher about 6 months ago but I did drain some water several times. For the last 6 months or so I've be researching all kinds of stuff on here so that's why I'm finally deciding to switch over to liquid chlorine. I just paid for the app the other day so I could maintain my logs on here. Also I had phosphates at over 4000 but thanks to everything I read on here, I treated with orenda and now they are normal! Anyway, I just really want to make sure that having free chlorine at 13 is okay since it seems so high. Thanks again for your help.

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chalking issue in a Fiber glass pool in ground -

Welcome to TFP!!!

99 times out of 100, the “chalkiness” you see is NOT calcium scaling. It the breakdown/hydrolysis/oxidation of the clear gel coat on the FG surface. There is literally nothing you can do about this to stop it. All gel coats will begin to breakdown from the oxidative stress of water, chlorine, and UV. It’s simply the physics and chemistry of water and polymers.

The only way to restore it is to have the pool drained, the surface lightly polished to remove the porous layer and then a fresh gel coat applied. It’s, at best, impractical to do and would be extremely costly as it is mostly back-breaking labor. Anyone that owns a boat or a classic car knows how hard it is to keep these types of surfaces polished and cleaned (gel-coats on fiberglass are very similar to clear coats on cars).

@Texas Splash may have more weight on the subject...
Thanks for the information. Seems to be the general consensus with the pool people around here( Venice , Fl) as well. Not many companies do the work and a first guess was around $7k for a straightforward 10000 gal pool. Yikes . I just had to have a skimmer replaced 2 weeks ago and that was $2300. The pool mainatence company I use said most folks just live with it. That is also a problem as the robotic cleaner I use sometimes gets stuck in a corner and the rubber wheels will spin and rub the coating down to the fiberglass leaving dark patches.
  • Wow
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