Sorry for the slow answer.

With FC > 11 ppm, you may have regained control of your pool. If not, do this:

1. Retest your CYA, using a 50:50 dilution of pool water with tap water. Multiply the results x2 for your actual CYA level

2. Read the Best Guess page, linked in my signature, or found here: http://www.poolsolutions.com/gd/best...ine-chart.html

3. Adjust your chlorine level upward to an appropriate level.

4. Stop using stabilized chlorine (trichlor or dichlor) and use only bleach. with CH = 280, you probably don't want to use calcium hypochlorite either, though there is a way to do so IF (a) you have a sand filter, (b) a working skimmer, and (c) can make SURE that any chlorine feeder located upstream of the filter is EMPTY.