2003,
Something is wrong with your tests, or you did something wrong...
You are spot on that 17 lbs of CYA will get you from zero to 75 ppm of CYA in your water...
Logic says that after 7 days that CYA should be well mixed with the water.
We call test strips, "guess" strips, but as bad as they are, they should have shown something...
How did you add the CYA?
What kind of filter do you have?
Did you backwash the filter since adding the CYA?
Do you have brand new water? If not, what made you decide to suddenly increase your CYA from zero to 75 ppm??
What is the current status of your pool water? Clear, cloudy, or green???
Sorry for all the questions, but things are just not adding up for me.
Thanks,
Jim R.