Pool Store Readings

[rboutwell]

Preface: I am a new pool owner as of 2/19/16. We purchased a home with a small pool (app 8,500 gallons). I'm a DIY, so I purchased a 6 way HTH test kit at WM. Since then, I've also taken samples to a pool store in town. Two recent analysis:

4/28 5/4
CYA 151/ 151
FC 15/ 10.7
pH <6.6/ 6.8
Alk 10/ 104
CH 127/ 402
I added 2 lbs of soda ash yesterday to attempt to raise pH to 7.2


On 4/28, it was recommended that I stop using any form of chlorine, drain off some water and add Balance Pak 100 6lbs (now I know that I was sold very expensive baking soda). I tested pH with the kit (I plan to purchase a better one on internet) and got the same reading of 6.8. My question is why the big upward swing in CH and what to do about it, if anything?

 

[Mr Bruce]

I'd trust the HTH over the pool store, pool stores are notoriously bad at testing. But you should upgrade from the HTH too, TFTestkits.net If I were you I would

1 Order the TF-100
2 Add enough borax to get the pH to 7.2 http://www.troublefreepool.com/calc.html
3 Add 1/3 gallon of bleach to the pool everyday until the new kit comes.

How does the pool look now? If that CYA number is even close you are going to need to drain

 

[Texas Splash]

At this point Ray, I'm afraid it really doesn't matter. The fact that your CYA (and CH) "appear" to be excessive would require a partial drain(s). But I would not judge the amount to drain based on the pool store's CYA test. That test is simply way too critical, and it's one test the store is notorious for getting wrong. You really need the proper test kit of your own to validate the CYA. I wouldn't waste much more money or time on the water until you know that CYA for sure. Please see the TF-100 link below in my sig.

Upward swing in CH? Hard to tell from those test results - again we don't have a lot of faith in the pool store. But CH is raised by pool store products and/or fill water. Anything beyond that could be testing error and inconsistencies.

 

[rboutwell]

The pool is crystal clear. I do plan to purchase the TF-100, hopefully today.

 

[Texas Splash]

That's a wise choice Ray. Most have no idea until they get the kit and do it themselves. I know I was that way at first. For now, I would just do the essentials - maintain pH and keep the FC a bit elevated. Remember that an FC over 10 skews your pH reading though. As soon as your kit arrives, make the CYA test a priority. That will drive everything else. And just so you have it now:

Proper lighting is important for the CYA test. You want to test for CYA outside on a sunny day, but keep the skinny view tube in the shade. Taylor recommends standing in the sun with your back to the sun and the view tube in the shade of your body. Use the mixing bottle to combine/gently mix the required amounts of pool water and R-0013 reagent, let sit for 30 seconds, then gently mix again. Then, while holding the skinny tube with the black dot at waist level, begin squirting the mixed solution into the skinny tube. Watch the black dot until it completely disappears. Once it disappears, record the CYA reading. After the first test, you can pour the mixed solution from the skinny view tube back to the mixing bottle, shake, and do the same test a second, third, or fourth time to instill consistency in your technique, become more comfortable with the testing, and validate the CYA reading.

 

[rboutwell]

Thanks Texas! I appreciate the mentoring. BTW, I'm a big Amazon freak. The only kit on amazon is the Taylor K-2006. Thoughts?

 

[Mr Bruce]

Check out this page Pool School - Test Kits Compared

 

[Texas Splash]

It's a good kit, but we normally suggest getting the K-2006 "C" (commercial) as that model has more reagents and is more comparable to the TF-100. That's why the TF-100 is so popular .... it uses Taylor reagents but in larger quantifies so typically it's looked upon as a better value.

 

[rboutwell]

Please excuse my ignorance; large learning curve here. What exactly is Chlorine OTO? The TF-100 is the only test kit that includes this?

 

[Texas Splash]

The OTO test is cheaper and faster to run. It's fine for daily checks and as a backup when shock levels can cause you to question what is going on with the FAS-DPD test. Also, the OTO test also never bleaches out, so if FC is above the test range, it goes through shades of orange and brown. A quick summary of each:
OTO - Quick and easy one-step (ballpark) total chlorine number
DPD - Mid-level test that can provide you both FC and CC (again, ballpark)
FAS-DPD - A little more effort to mix & use drops, but tells you to the .5 ppm level both FC and CC; NO color matching required; just drops until solutions turns pink or clear

Me personally, I almost always use the FAS-DPD for accuracy each day. That's just me.

 

[pabeader]

I just checked and the "C" version of the K-2006 is over $90 on Amazon. I think the TF kit is a better deal...Even order the XL option is still better.