Are you sure you are using your kit properly??!!

I have 2 different kits, 1 is part of a Taylor kit. Directions for that kit uses 7ml pool water and add another 7ml of 0013 reagent in a seperate tube----You shake and wait then add the mix slowly in the tube with the black dot on the bottom until the dot just disappears--then read the mark at the water level..100 is near the bottom. The more of the mix it takes for the dot to disappear --- the lower the CYA.

My second test kit uses a slide with a dot on it. Again equal quantities of pool water and 0013 reagent ---- mix with the slide, wait, and begin raising the slide till it just becomes visable and read the scale at the water line Not the slide bracket at the top.

If your CYA really is high --- use double the pool water compared to the reagent then double the reading for better accuracy.

Hope you are reading incorrectly and don't have to drain any more.