Calcium Hardness test question

[JJoe]

During the calcium hardness test (Taylor) reagents seem to not dissolve/dilute evenly. Am I not swirling good enough? Is that just the way it is? Or do I need the auto stir?

 

[Dirk]

Pool School - Calcium Hardness

See the Notes section about interference.

The SpeedStir will help. And you'll be kicking yourself for not getting one sooner!

 

[JJoe]

Thanks for the link. There's so much great information on this site, but it's easy to miss unless somebody puts it in front of my nose. Thanks again, am looking forward to trying the modified test.

Little freaked out by possible interference from metal "ions". Is that just a term that means there is metal in the water? Or does the "ions" mean something different?

I have seen and dealt with suspected iron staining in the past and have metal Magic in the water as a sequestrant now, but the ion term has me wondering.

 

[Dirk]

Yah, that stuff is way beyond me, though there are some here that know it. I'm not even sure if the modified test will address your purple spots, so one step at a time. And it's my understanding that sequestrants don't remove anything, but just bind it up to keep it off your surfaces. Which might mean it's still available in the water to mess with your test. I'm just bumping to catch the eye of someone more knowledgable.

I also seem to recall a process that actually removes metal. It's a vague memory, something about putting a cloth-like material in the water that attracts and absorbs. I think that was iron. Let me send out some feelers on that...

 

[duraleigh]

Dirk has it right. The iron in your pool is kept in soluble form by the sequestrant but it is still in there and still interferes with the test. Try the 5 drops of R-0012 first and see if that doesn't stop the issue or at least help it to the point where you can complete the test.

 

[Dirk]

Thanks Dave!! Do you happen to remember the thread where some guy floated some kind of material in his water, or maybe put it in the skimmer, and it collected iron out of the water? Or he built some kind of contraption that had material in it, that he ran his water through that did that trick? I seem to recall pictures, and that it turned orange, which made me think of iron.

- - - Updated - - -

Here's something (but not exactly the thread I remember):

If you’ve got iron in your fill water, use Polyfill to remove it

A forum search of "remove iron from water" brought up many hits.

 

[kimkats]

That was the one I was going to try to find for this thread. Great ideas in it. THANKS DIRK!

Kim

 

[bo_mull]

Nevermind

 

[JJoe]

Tried a few tests using 5 drops of R-0012 first. Still had some spots in it but they seemed to be smaller.
Once it turned blue the spots could not be seen.

I had also always been using a 25ml sample. Switching to a 10ml made the color change much easier to see even with it being a blend from purple to blue.

First time I tried it I used 10ml sample, put 5 drops R-0012, 10 drops buffer, then 5 drops indicator (used to doing 5, instead of 3), then adding on to the 5 drops R-0012. This test gave me the most dramatic change to blue of any of the tests I tried. Definitely easier to pinpoint the change than any I had ever done. Does having to much indicator in it throw off the results?

Results from all tests I tried (including the tests I did before I started the thread) showed the same general result/*guess*. Around 270-280 ppm (275-300 for 10ml samples). Does the metal ion interference just make the test harder to read? Or does it throw off the end result?

Just wondering how reliable my results are? Even with getting repeated similar readings.

 

[Dirk]

I don't know the answer about the "too much indicator" question. I'd say follow the directions exactly for best results.

Let's see if someone else has a "scientific" answer about the accuracy with metal present. I'd say it's fine, or else the extended directions I sent you to would have mentioned it.

Your results are fine.

Please update your signature. You're not doing yourself any favors asking for advice with a signature that is not accurate and up to date.

 

[duraleigh]

The test is still valid despite presence of metal in your water. Your good to go calling it 280 ppm and don't over think it.

Who tested that commercial pool before you? Was CH never tested?

 

[JJoe]

I was shown how to do the test by the person before me. Their instructions just matched the Taylor kit instructions. They did not keep track, nor did I until recently, of the Calcium test results on a regular basis. Tests were generally performed once per week, but results not recorded diligently. I believe because the results have always been within range. I have been paying more attention and worrying about the test now because we made the switch from Bromine to chlorine.

We went from bromine tablets to 73% cal-hypo granular on a trial basis. Did a complete drain and refill to make the switch. Fill water Calcium tested at 170-180. Been monitoring cal levels more closely so I could recommend making a switch to liquid cl when/if we need to. As I am drawing closer I really want to be able to be confident in my test results before I suggest switching to liquid Cl.

 

[Dirk]

They're lucky to have you, Joe...

 

[duraleigh]

Yeah, they are lucky. Your thinking is solid......nice work.

chlorinating with Cal Hypo is certainly convenient but has a couple of drawbacks.....

1. Water can cloud easily. It's temporary but disconcerting until the CH all goes into soluble form

2. For every 10 ppm chlorine you add to the pool, you add 6 ppm Calcium. So if you consume 5 ppm daily fc, you are adding 3 ppm CH. Doesn't sound too bad until you realize that's 90 ppm per month of CH

 

[JJoe]

Thanks for the votes of confidence. I have learned a lot from lurking on this site and have gotten great info when I have posted questions. Still have tons to learn, trying real hard to learn here and not from mistakes.

I skipped out on a certified pool operator class so far because of what I can/have learn(ed) on here and because I could not find a class that wasn't put on by an outfit that also sells pool supplies.

 

[JamesW]

You should get CPO certified. It's required to operate a commercial pool.

National Swimming Pool Foundation

 

[JJoe]

It is definitely still on my list to do, and I have a list of a couple of recommended instructors (even though they are still employees if a pool store). I am sure I can still learn plenty from one to.

I would like to ask who it is required by? It is not real clear what set if codes we should be following. (Probably something I would learn in a local CPO class!)

 

[JamesW]

A public pool is usually under the authority of the health department.

Does the health department require a permit and inspections?

They usually require a permit and inspections. They want a CPO to be responsible for the pool and they want proper records of chemistry tests.

The Health Department’s inspects all public and semi-public pools, spas and hot tubs in Kansas City, Mo. Pools are inspected on average once per month during a season. Except for the opening inspection, all routine inspections are unscheduled.

Pool operator classes

Pools, spas and hot tubs licensed by the Health Department are required to have a certified pool operator on staff or on contract, according to the “Public Health Rules and Regulations for the Operation and Maintenance of Swimming Pools and Bathing Facilities“.

To satisfy this requirement, pool operators may attend classes offered at the Health Department at a cost of $50 per person, payable by cash, money order or corporate check (no personal checks).

The Health Department also accepts certification through the National Swimming Pool Foundation and the National Recreation and Park Association, both of which offer local classes.

KCMO.gov Pool, hot tub and spa inspections

State, County, and Country Codes | National Swimming Pool Foundation

The Aquatic Facilities Program is responsible for approving and regulating public and semi-public pools, wading pools, special use pools and spas. Public and semi-public pools and spas are typically owned and operated by municipalities or businesses such as hotels, apartment complexes, homeowners’ associations, churches, schools and other governmental, non-profit or commercial enterprises.

The Division of Environmental Health and Protection licenses and inspects pools and other aquatic facilities in unincorporated St. Charles County, as well as in the cities of Dardenne Prairie, O'Fallon, St. Charles and Wentzville, to monitor proper operation and facility maintenance.

Pools Spas | St Charles County, MO - Official Website

Section 233.120 Pool Operator Certification
A. All permitted aquatic centers shall have a minimum of one (1) nationally
certified pool operator on staff. This individual shall:
(a). Be present on property thirty-three percent (33%) of operating time.
(b). Be directly responsible for maintaining the cleanliness, water quality and chemical balance of the aquatic center.
https://www.sccmo.org/DocumentCenter/View/1686

 

[JJoe]

We are not permitted and do not have local health department code or inspections. We fall back to the CDC aquatic health code for our operating guidelines/regulations. Not really sure if that puts us under any type if regulating agency or not.

Thanks for finding info for me. I was tasked with looking into that when I first started, found those links, and decided that we didn't fall specifically under anything listed. Always was afraid that I had missed something, but I haven't had any inspectors come knocking yet...

 

[Dirk]

Makes you think twice about jumping into hotel pools if you're traveling across the states/world... the curse of knowing TFPC! Should we travel with our test kits?

I don't count hot tubs. Anyone crazy enough to get into a public hot tub is just askin' for it...