I took my pool water to two pool stores today for testing. The first store used an automated dip stick type test and gave the following results:
FC: .5
CC: Not given. Based on FC and TC it would appear to be 0 which I know is wrong.
TC: .5
Ph: 7.0
TA: 88 Note, it also gave an Adj. Total Alk = 73. I assume this is a correction based on the Ph and CYA levels.
CYA: 49
Hardness: 229
The other store used individual test vials. I would think this would be more accurate. Results are:
FC: .1
TC: .8
CC: .7
Ph: 7.3
TA: 78
CYA: 72
Hardness: 219
I measured the CYA and my guess using the black dot test is around 60. I'm never sure what the real endpoint is on the black dot test. I can always see the dot in some form. I assume they mean when the dot color blends in with its surroundings. Any help with how to interpret this test would be appreciated.
These CYA levels are quite a bit higher than the last time I tested it. Perhaps this is because I have been using a lot of Trichlor tabs in an attempt to keep the pool from getting out of control while trying to solve the FC problem.
Regarding the bucket test, I checked it this morning and FC = 0, CC = .8. I added another 1/4 teaspoon and FC = 16.5, CC = 1.0 and Ammonia = .25. As before, the FC shot way past the expected 10 ppm. Is it possible the bleach I have is considerably stronger than advertised? This may explain part of the inconsistency between the expected amount of beach needed based on the ammonia level and the results of the bucket test.
I'm curious about a couple of things. My basic understanding (and possibly wrong) is that chlorine should react with the ammonia to form chloramines which should show up as CC. So, why does adding chlorine appear to reduce ammonia levels without raising CC levels?
Also, I have read many places if you are shocking and don't get the FC level high enough to reach breakpoint, you have wasted your money and probably made the problem worse because the chlorine is just going to produce a higher CC. My (possibly stupid) question is, if you have a high level of CC that requires an unusually high amount of chorine to reach breakpoint, can you turn the pump off (at least initially) and put the estimated bleach amount in the shallow end to force a much higher initial FC level in the shallow water in the hopes of reaching breakpoint on some of the water if not all of it? This way you would at least make progress on it.