Ran out of CYA Reagent so went to the pool store..

[Rocknik]

Pool water looks great but it was time to test..
I know, I know.. the pool store's #s are never accurate but I ran out of the CYA for my Taylor k2006 test kit and figured they could at least give me some kind of guidance (it's also 2 mins down the road from my house) before my new shipment arrives from Amazon. The thing that I find most interesting however, is how differnt my FC #'s are vs. theirs. A few weeks ago, I tested and noticed that I had hardly any chlorine (1. somthing) despite there being no algae in the pool. I cleaned our the salt cell, added some stabilizer (which was also low) and a day later the numbers climbed from 1 to 5, and eventually to where I wanted.. Fast forward to today, I tested and these are my #s from the Taylor Kit:
FC - 8.0
pH - 7.8 (this is always a bit of a guess between 7.8 and 8, hard to tell)
TA - 180 (I've always had a very high TA, since I moved in.)
CYA - (last reading was around 90 didn't have the ability to test today
CH - 120
Salt - 3k

Pool store readings:
FC - 11.5 (***!!! How could this be that different? I don't really open my eyes under water, by kids do. As do others who come over, there's some redness but never complaints of any pain**!!)
pH - 8.0
TA - 150
CYA - 82
CH - 106
Salt - 3k
Phosphates - 985

So with that, I have a 2 part question
1. How could our chlorine #s be so far off?
2. do you think I should try lowering the ph (which if I am correct will also lower the TA) and then aerate to bring it back up?

29,000 Gal Vinyl pool with T15 SWG

 

[PoolStored]

1. How could our chlorine #s be so far off?

I know, I know.. the pool store's #s are never accurate

Seems you answered your own question.

2. do you think I should try lowering the ph (which if I am correct will also lower the TA) and then aerate to bring it back up?

I would lower your Ph to 7.4. Let it rise, or aerate until it gets to 8.0. Repeat the cycle until your TA gets to 60-80, then STOP lowering pH to 7.4. Your pH should be pretty stable around 7.8-8.0 with a TA of 60-80.

As do others who come over, there's some redness but never complaints of any pain**!!)

What is your CC? When was the last time you tested CC?
Test CC and do this test tonight...Link-->Overnight Chlorine Loss Test
11.5 is not high if your CYA is 90. Always follow this...Link-->FC/CYA Levels
How are you chlorinating?

 

[Rocknik]

Cc is 0
Chlorinating via swg

 

[wireform]

With a CYA of 90 you'd be well advised to do a diluted test.

 

[Rocknik]

Diluted test?

 

[wireform]

Diluted test?

Please explain how to dilute CYA test if over 100

 

[ajw22]

Diluted test?

Water Testing Instructions - Further Reading

www.troublefreepool.com

For CYA > 90ppm, repeat the test adjusting the procedure as follows:

1. Fill the mixing bottle to the lower mark (15 ml line) with pool water.
2. Continue filling the mixing bottle to the upper mark (30 ml line) with tap water.
3. Shake briefly to mix.
4. Pour off half of the contents of the mixing bottle, so it is again filled to the lower mark (15 ml line).
5. Continue the test normally from adding R-0013, but multiply the final result by two.

If you need to dilute the pool water further then apply these ratios:

Pool water	Tap or distilled water	Multiply result by
1	1	2
1	2	3
1	4	5

Note that when doing a diluted test not only do you multiply the range of the test you multiply the error rate of the test, so results are a ballpark - not an absolute.