Test Results Show High Calcium Hardness & Total Alkalinity

[gslightner]

Got new water in the pool and it finally looks amazing! Using the Taylor Complete kit I ran a set of tests on 2 consecutive days and have the following results.

pH = 7.4
TA = 120
FC = .5
CC = 0
CYA = 39
CH = 520

The CH is really high. We just drained the pool almost halfway and had 9600 gallons of water trucked in to fill it back up. I did read somewhere that the best way to reduce the calcium levels is to drain & refill the pool, since we just did that, we would like to look for a 2nd best way of reducing the CH.

As I was looking for a sequestrant to use I also recall some products that were labeled as flocculants as well. Would those work to help make calcium particles become larger so that it could get filtered out? Has anyone tried this or can recommend another way to deal with high CH levels?

Also our TA is kind of high. The process I came across to reduce TA is to aerate it I believe it said. Is there another way?

We are adding chlorine to raise our FC. The pool looks AMAZING right now. Wondering if we should be very concerned with the high CH and TA levels.

Thanks so much,
Grace

 

[Richard320]

Okay, where do we start?

Let's start with the number 520. That tells me you did the test with a 25 ml sample and it took 52 drops. Stop right there. That's waaaaaay too much manual swirling. If you're using a speedstir, that's one thing, but manual? Forget it! Your wrist will give out and the test will get rushed. Next time you test, use only 10 ml water, 10 drops R-0010, then 3 R-0011L (although if it's too pale, you can use 4 or 5) then count each drop of R-0012 as 25 ppm. Because there's less swirling, your wrist will last longer and you can mix more thoroughly. I'll betcha your next test comes out lower than 525. It wouldn't surprise me if you came up lower than 400. It happened to me when I switched to a speedstir. The extra swirling really makes a difference. The smaller sample size is plenty accurate when you're up in the high numbers.

Don't use flocculants. Ever. And a Calcium sequestrant is unnecessary, if there even is such a thing. My CH is over 800. There are plenty of people throughout the Southwest who also enjoy such numbers. It's not ideal, but it's easily manageable. Play with poolmath. Plug all your numbers in and look at the CSI calculation. Then go through and change things one at a time. See what raising pH does, and temperature, and TA, and CH. If CSI gets to .6 or better, it's almost certain you'll start developing scale -- grow-you-own sandpaper on the walls that will cause roadrash instantly to any elbow or knee that brushes it. CH has a lot smaller effect than you might imagine.

Ch is the hardest to correct. Temperature is up to Mother Nature. You can control pH and TA, though.

TA needs to come down some. It's sort of a ratcheting effect. Acid lowers pH and TA. Aeration (including splashing kids) drives pH back up but TA remains the same. Since your CH is on the high side, drive the TA down aggressively to 80 or less. Then when pH rises to 7.8, CSI will still be in the safe zone.

 

[gslightner]

Thank you profusely for your advice!

I retested the CH using a 10mL water sample. This time I got a CH value of 875 as opposed to 520. I added R-0012 (drop & swirl) & the sample gradually went from pink to purple and I stopped adding drops when the sample looked completely blue.

The CH testing instructions from this website https://www.troublefreepool.com/content/218-Calcium-Hardness says that purple indicates a “Fading endpoint”. So I retested using the alt method suggested, the sample still went through a purple phase before turning blue, but this time I got a CH value of 700 and I stopped adding drops when it was mostly blue (still faintly purple though).

Can you advise on a few things? Is purple not supposed to show up at all during the test? If purple is allowed to show up, do I stop when the sample is starting to show signs of blue, turns mostly blue, or when there is no more traces of purple?

My CH results have been all over the place because I am uncertain of when to stop adding drops and because of my confusion of the purple color.

Will retry the test using the dilution method once I get a bottle of distilled water at the store later today. Hopefully this will allow a purple free test.

Thank you so much again.

I plugged in the values in the pool math app and even at CH=875, it indicated that our CSI value looked good at .28. So would it be safe to say CH is not a concern?

Gratefully,
Grace

 

[Richard320]

Purple (I call it indigo) is common, at least for me. Keep going to blue. When it goes blue and another drop doesn't change it, subtract that last drop that did no good and you have your count. Often, another cycle of the speedstir - one minute - is enough to push it to blue, without adding any drops.