What's a good cya lvl

[shocker1215]

I have read a few different number for a good cya lvl some have said 50 and others 80. I have mine at 69. Also with goods cya levels how much longer should the chlorine stay in the pool then having very low cya. My FCL and TCL were 3.8 5 days ago and now it's almost at zero. It did rain a couple days does that have anything to do with it also. I have a 20 by 40 in ground pool and my tests from today were

FCL-0.39
TCL-0.39
PH -7.6
ALY-119
CH -110 I have a liner pool
CYA-69

Thanks for any help.

[CarlD]

If your CYA is 70 (how did you get 69????) then your ideal FC level is from 5-10ppm. You shock by raising FC level to 20ppm

IF your numbers are correct (and I wonder), all you need to do is raise the FC to between 5 and 10 ppm. All the other numbers look good.

[shocker1215]

What's wrong with the numbers? I hope my numbers are right I spent over a $100 on LaMotte 2056 ColorQ Pro 7 Digital Pool Water Test Kit. The reason I got the digital tester is I had trouble seeing the colors good enough with the color testers.

[CarlD]

I've just never seen any numbers that close. I confess I know nothing about digital testers--or, more importantly, how to calibrate them.

With drop testing, unless you have extreme red/green color blindness--and people do, other than pH testing, the color changes are rather drastic:
FC and CC go from pink to perfectly clear with FAS-DPD.
T/A changes from bright green to bright red
CH changes from red to blue
CYA/Stabilizer has no color change at all, just a measure of how cloudy or clear the water is.

Only ph (and if you do OTO chlorine testing) require perception of color gradations.

We don't recommend strip testing. I have unusually good color perception, especially for a male (annoys the heck out of my better half! :) ) and yet I find the "guess" strips hard to read. They told me just today my CYA level was about 40 when in fact it was 60. (I use them for rough'n'ready quick testing to see if my chlorine is 'way low or my pH is 'way out of wack--either requires proper drop testing).

[PoolDoc]

Just finished a Color Pro discussion elsewhere. It's here if you want to read it: http://www.poolforum.com/pf2/showthread.php/23450

If you want to see how the K2006 kit works, you can watch these videos: http://pool9.net/tk-guide/.

Regarding CYA levels, you can run your pool at anything from 20 - 200 ppm -- but you have to adjust chlorine levels accordingly. See http://pool9.net/cl-cya/ SWCG (salt water chlorine generator) makers usually recommend (or require) levels from 60 - 80 ppm.

. . . membership updated.