FC not appearing on Taylor test kit

[rj101]

I've got a Leslie's "complete" test kit - uses Taylor DPD test reagents (R-00001 and R-00002). Pool is green and cloudy, so dumped 8 gal of bleach (6%) in pool and began testing (33,000 gal, CYA 60-70). FC never appeared - drops sort of flash pink/reddish when they hit the sample, but go clear. Tested straight bleach from bottle to see if it had gone bad, but same result (house brand just purchased from local Wal-Mart). Got new bottles of reagents for test, but same result. I could have sworn that last year the test showed the chlorine levels from bleach in pool water. Water where stablized puck sitting shows expected level of FC. I know it is sodium hypo rather than calcium hypo, but ends up as "chlorine" in the water, so why don't the reagents indicate some level - even in straight bleach?

[PoolDoc]

Most DPD reagents -- but not those in the PS234 -- bleach out, in exactly the manner you describe, if the chlorine level is 10-15 ppm or higher. Straight bleach, at 50,000 - 60,000 ppm, will bleach all DPD reagents out, including those in my PS234.

Ben
"PoolDoc"

[rj101]

Thanks Ben; that certainly makes sense. I am confused though, because I'm sure that some of the water I tested at some point was well below 10 ppm (no bleach added for 3-4 days and algae blooming back with a vengence) and the same water in the skimmer where a puck was sitting (pump off) registered about 3 ppm and today tested - no FC but about .5 to 1 ppm CC. Is there anything else that could be going on to knock the FC to zero so fast?