Confused

[darylfoot]

Did my 1st tests with TF100 last night.

13200 gal
FC 2.5
PH 7.8
TA 130
CH250
CYA 50

I wanted to go up to 8 FC, Pool Calculater said add 151oz of 6% bleach. I added whole 182oz of Wal-Mart 6% bleach. Tests now are

FC 14
PH 7.8
CYA 50
CC was 0 on both tests.

Why did it raise the FC so much?? Great website and forum, BTW. Pool was installed in November so I'm still learning

 

[JasonLion]

Welcome to TFP!

There are several ways that could happen. The most likely is you entered the the wrong size for your pool, larger than it actually is, into the Pool Calculator.

 

[duraleigh]

Welcome to the forum. :lol: Well, you used the calculator correctly, I think. How sure are you on the size of your pool?

 

[darylfoot]

It's 14x28 in ground vinyl. Installer said it was 13,200 gallons

 

[duraleigh]

Well, that sounds about right, also. The next best guess is if you are new to the test kit, a testing error is a common issue. review the steps....did you multiply X.5 to get the answer?

 

[darylfoot]

It was 28 drops. The test was taken 2.5 hrs later. Pump is running 24-7 til I get a timer this weekend. I'll test again tomorrow when I get off work

 

[linen]

Welcome to tfp, darylfoot

It was 28 drops. The test was taken 2.5 hrs later. Pump is running 24-7 til I get a timer this weekend. I'll test again tomorrow when I get off work

This has me stumped (a possibly silly question for you...you don't have a swg or other chlorinator running, or perhaps a floater or forgotten pucks in skimmer by any chance?)...let us know what your next results are.

 

[Beez]

Haven't I read somewhere on the forum that bleach is commonly stronger than the % listed on the label? Stronger bleach together with a slightly over estimated pool volume could cause the anomaly...

 

[duraleigh]

Haven't I read somewhere on the forum that bleach is commonly stronger than the % listed on the label?

No, I think you have to be concerned that it is possibly weaker but seldom, if ever, stronger.

MY LQ guy said the 12% I use is manufactured at around 14% but that it quickly starts to lose strength and by the time it gets to the consumer, is right around 12ppm......and they buy chlorine twice weekly.

However, that 12% chlorine weakens MUCH quicker than 6% so it will last on the shelves of the store and in your garage quite a bit longer (weeks) but it does slowly weaken.

I do remember a chart someone posted showing the degradation but I searched and didn't find.

 

[darylfoot]

OK, checked my FC tonight and it was at 5. I'll check again tomorrow and see what's up...

 

[JamesW]

http://www.powellfab.com/technical_info ... tware.aspx

The Powell Sodium Hypochlorite Decomposition Program generates graphs and tables illustrating the decomposition of sodium hypochlorite based on the user's selected temperature, starting weight, and bleach quality.
The user can automatically generate tables and graphs depicting the decomposition of sodium hypochlorite over time (between 1 and 360 days) for up to four various scenarios based on the selected temperatures, starting weights, and quality of bleach (filtered or non-filtered).
The Powell Sodium Hypochlorite Decomposition Program is available for free.

 

[ping]

When you add any chemicals make sure you test the water again 1-2 hours after adding the chemical. If you don't get the results you expect then we'll go from there.

I always add more water to my test cylinder after running the FC test to make sure the water turns pink. If you don't put enough powder in the test, the water will not turn pink and the test should be redone with more powder than the first test.