after availing myself of the wisdom on this forum for the past winter i was beginning to think i was getting the hang of the BBB system and was able to keep a pretty stable hot tub without too much fuss... relying on the results of the Taylor K2006 and using it almost exclusively to test the water. so, today - after we luxuriated for a long soak - i added 6 oz of bleach, circulated the water for 15 minutes, and then tested our 350 gal hot tub.
with a test strip it shows 3 ppm of FC - but using the Talyor K2006 at the 25 ml level it takes 15 drops (!!!) for the sample to clear = 30 ppm. repeated the tests - same results. i just bought fresh 870 & 671 reagents (and test strips), and am unable to reconcile the extreme difference in the readings.
there is no chlorine smell, the water is clear, and given the volumes of liquid bleach i'm using to sanitize, the Pool Calculator would tell me that the test strips are closer to the right answer...
any suggestions for where i am getting things wrong?