Discrepency btw store's H20 test and PS233

[22wendylou]

Checked my pool today using quick PS200 kit and got alarmingly HIGH chlorine results:

TC= Dark Orange (beyond readable)
pH= 6.8

I purchased new hth chemicals for this quick kit from Wal-Mart this past June 2010. Shocked to see such a high cl level, I decided to 'pull out the big guns' and use my DPD test. {My titrating reagent and powder are a couple years old}...My result was:

FC= 37!!! Yep, I used 74 drops b4 the pink color disappeared in the water sample

CYA= 90 when I opened the pool in May. (I'm out of the reagent to re-test it at the time of this post... But, I have been keeping my cl level high approx 8 due to the high CYA)

I typically add approx a cup of powdered chlorine a day or 2c every other day...{Gave up on liquid bleach-too many suits/tee's bleached out}..Water has looked beautiful...Clear, blue, etc, since opening 2 months ago..

Anyone ever experienced such varying test results? No one's been complaining of red eyes, rashes, etc. I HAVE noticed my daughter's hair has a green-ish tint. I was going to add some Metal-out soon....

Here are *my* readings in full:

TC= Off the charts orange
FC= 37
pH= 6.8
TA=50
CYA= 90 (taken May 2010)

Here are the store's readings in full:

TC= 1
FC= 3
pH= 6.8
TA= 80

My pool is a 28ft round above ground with an 8ft deep end = approx 26,000 gallons..Sand filter, vinyl liner. Any advice would be greatly appreciated....

I should add that I've used both the quick testkit PS200 chemicals and the PS233 kit all summer with what I thought were normal readings. This result today was the first of its kind....