Combined Chlorine Test

[Jakebear]

I must be doing something wrong!!! In 4 years I have never measured any CC in my pool!! That’s great you say, but I am sure there are some.

Today I violated this forum’s recommendations and took a sample to three different stores. My sample showed between 2 and 3 ppm CC at the stores. The stores all tried to sell stuff but I wasn’t buying.

I do my tests per the kit instructions, being very careful and keeping everything clean and fres reagents. I'm doing both standard DPD and FAS-DPD. Never is there any CC. Is there some trick I’m missing?? Surely the stores don’t spike the reagents to give “Sales” results --- especially 3 out of 3.

By the way I did go to Walmart ---- 182 oz Clorox Ultra for $5.00. Picked up 10 for my cloud removal tomorrow.
Edit --- Standard Clorox Ultra --- Mis-typed or brain fart??
My results for today are:--- Store Results
pH 7.7 by titration ---- 7.3 -- 7.6-- 7.6
FC 7.5 ppm (FAS-DPD)--- 5.9-- 5.2-- 5+
TC 7.5 ppm (FAS-DPD)--- 7.0 -- 7.6-- ??
CC 0 ppm (FAS-DPD)--- 1.9-- 2.4-- ??
TA 90 ppm (by titration)--- 85-- 62-- 125
CH 280 ppm (by titration)--- 205-- 190-- 210
Phosphates <100 ppm--- NT-- No test -- NT
CYA = 60 --- 75-- 60-- 60
ORP = 755--- NT-- Nt-- NT
TDS--- NT-- 890-- 1500

Edit This all ran together --- My results are first then store 1 store 2 etc. separated by--

[duraleigh]

Hi, Jake,

Those are surprisingly consistent results for pool stores. It certainly sounds like there's something wrong with your test chemicals (probably) or your test methods (not likely).

It sounds like you'll need to replace some chemicals.

[Jakebear]

Thanks Dave

I just got the FAS--DPD kit from Taylor 2 weeks ago --- and my R-0003 from the standard kit is fresh for 2006. I've used both methods -- same results--no change in color (still clear with FAS-DPPD method) after adding that reagent!!

I wish Taylor would date their Reagents --- there doesn't seem to be any rhyme or reason to the batch number.

My results this morning are the same except FC dropped to 6.5 and the pH 7.5

[larry2338]

Quote:

My results for today are:--- Store Results
pH 7.7 by titration ---- 7.3 -- 7.6-- 7.6
FC 7.5 ppm (FAS-DPD)--- 5.9-- 5.2-- 5+
TC 7.5 ppm (FAS-DPD)--- 7.0 -- 7.6-- ??
CC 0 ppm (FAS-DPD)--- 1.9-- 2.4-- ??


What kind of CL test returns results like 5.9 - 5.2 - 7.6 - 1.9 - 2.4 - etc???

[ubalr1]

According to the MSDS sheet for Clorox Ultra 2, in addition to sodium hypo it contains Hydrogen peroxide 1-5%, Alkylbenzene sulfonic acid 6-10%, and Triethanolamine 1-5%.

Why would you want to add these extras to your pool?

I'd stick to the plain Clorox Ultra, or better yet the generic ultra bleach. Same stuff but cheaper.

Poolsolutions recommends staying away from the Clorox brands because they add "goo" to their bleach (http://www.poolsolutions.com/gd/bleach_0525.html) and here (http://www.poolsolutions.com/gd/ultrableach.html).

[Jakebear]

See edit --- I had a brain fart --- it is standard Clorox Ultra. Thanks for the catch!!

[Jakebear]

Larry,

I use a FAS-DPD kit (Taylor K-1515A)---using a 25ml sample you will get a resolution on the end point within .2ppm --- That is 2/10ths

The results I posted were a mix of mine and pool store --- Some stores use a colorimeter which yields results to .1 but since I don't trust the stores techniques or calibrations (if they did any) --- you can probably round their numbers off to the nearest whole number.

[waterbear]

Larry,

I use a FAS-DPD kit (Taylor K-1515A)---using a 25ml sample you will get a resolution on the end point within .2ppm --- That is 2/10ths

The results I posted were a mix of mine and pool store --- Some stores use a colorimeter which yields results to .1 but since I don't trust the stores techniques or calibrations (if they did any) --- you can probably round their numbers off to the nearest whole number.

IF they are using a LaMotte Waterlink colorimeter then they are not waiting for the TC result to stop moving on the meter. I have seen this happen where I work when inexperienced people do the test. The FC test needs to be read within 30 seconds and the TC needs to be read at 1 minute for accurate results!

[medvampire]

A few weeks ago when I was salting my pool I had the pool stores test my water. The results they gave me didnt agree with my testing for CC as well as pH. The tried to sell me shock and dry acid for a pH of 7.6. I have lost my faith in most pool store chemist.
Evan (waterbear) you know I dont include you in that statement.
Steve