Importance of Calcium

[Pool Dad 85]

Opening a 24 foot above ground pool for the 2nd year. One week into the process. Pool is clear and running for 7 days. I'm working on the TA as we speak.

I've been hanging in the weeds here and there for the last year so I understand much of what goes on here in connection to chem but I don't understand the importance of calcium. I have had others in the past year tell me to largely ignore the readings on an above ground pool. Pool was great last year but I'm always up for learning more.

Test -
FC - 1.78
TC - 2.01
PH - 7.4
TA - 49
CH - 67
CYA - 47

 

[mknauss]

Welcome to the forum!
Those appear to be Pool Store test results. Do you have your own kit? If so, please post results from your won testing.
Your FC is far too low IF your CYA is 50. Please review FC/CYA Levels. Also, the TA is OK. Allow the pH to rise.

Calcium hardness on the low side is not an issue for liners. Though many find needing 50+ppm in the water to keep it from foaming.

I suggest you read ABC's of Pool Water Chemistry and consider reviewing the entire Pool School eBook.

 

[Pool Dad 85]

So calcium over all not a majorly important figure for above ground pool chem?

 

[mknauss]

On the low side, no. On the high end, yes.

 

[Pool Dad 85]

Thank you for the response. I've never encountered foaming so I'm going let it stay there for now.

 

[splashpad]

So calcium over all not a majorly important figure for above ground pool chem?

FC, PH, TA, Temp, are the vital vinyl pool factors =)

Thank you for the response. I've never encountered foaming so I'm going let it stay there for now.

With 67, you shouldn't

 

[cfherrman]

With pool store testing that number is in the range of 6.7 - 6,700

 

[Texas Splash]

Pool Dad .... Welcome! Like everyone else already noted ..... this topic goes way back: Question about the need for calcium in vinyl pools

As for pool store testing though ......

 

[Pool Dad 85]

i know may here decry testing at a pool store. What's the evidence you have for their methods to be inconsistent with the Taylor kit?

Each store doesn't use the same testing equipment so it can't all be lumped into the same bag.
And quite frankly it works for me getting water tested there. I've have a crystal clear pool for a few years now. I use household bleach 90% of the time, I don't buy the add on snake oil they sell, over all I'm pretty happy with how I'm doing it.

But thanks again for the calcium clarification.

 

[cfherrman]

Because they don't care

If they are wrong they make more money

 

[Pool Dad 85]

Because they don't care is not a scientific reason or proper evidence to say testing is inaccurate.

 

[cfherrman]

Stay here awhile, it is very rare to get someone with a accurate test result.

Want to try yourself? Take the same sample of pool water to 3 or more pool stores

Was that 3 drops or 4? I'll go with 4

Testing the cya test inside

Not calibrating the unit at all

Expired components

Etc

Typically I saw to take pool store testing straight to the trash

 

[Texas Splash]

What's the evidence you have for their methods to be inconsistent with the Taylor kit?

PD, as to not make it sounds like an "us versus them" mentalilty, I will give you my recent personal experience. Occasionally I get my water tested at the local big-name pool store. Why? ONLY because I may attempt litigation with my pool manufacture (Viking) at some point, so I am simply coloring between the lines per the manufacrure warranty. I do all my own testing with a TF-100. But here's where it gets funny. We know CYA and CH will not drop unles you exchange water right? I can have testing done one week at the local store with a CYA of 70 and CH of 300, then the following week they show a CYA of 40 and CH of 130. I've also notced the TA results vary by anywhere from 20-30 ppm each week. FC and pH are fairly close, but they should be. Those two tests are extremely easy.

So why does this happen? Our experience, and by "our" I mean thousands of TFP member feedbacks, it boils-down to seasonal employees who don't really know chemistry, only doing what they were told, rushing to get a long line completed, and poor lighting. Incondescent lighting can really disrupt viewing, especially for the CYA test. We all know most products at these stores are way overpriced, and in many cases not even needed (i.e. PhosFree, Weekly stuff, ScaleTec, etc). Yet the clerks push those products for revenue. It's what they do.

Here at TFP we make no money from your pool or business. Everyone here are volunteers and have been through the same thing. Home testing is and always be much more reliable than at the store. Are there exceptions?..... occasionaly. In fact, you may find a clerk somewhere who really knows their stuff, but in general, their testing will lead you astray, wasting time, money, and only getting frustrated. Hope that's more of what you were looking to hear.

 

[Pool Dad 85]

TS - Much more along the lines of what I'm curious about. I'll keep all my test results this season and see if I can track a disparity or not.