Quote Originally Posted by Hurricane1938 View Post
I have been adding ~2.8 gal of 6% plain bleach each evening, but by morning my FC=0.
Increase the dose to 8 gallons -- about 20 ppm -- and brush after you dose. Discontinue use of the polyquat will doing this; that much chlorine will break the polyquat down.

Test chlorine levels the following evening, and add 1 gallon of bleach for each 2 ppm below 20 ppm; ie. if FC=10, add 5 gallons. Continuing dosing in this manner for 5 days. Brush the pool completely again at some point after the first large dose.

Then, skip one dose, and test FC both evening and the following morning. You're checking to see what the overnight (no sun) chlorine loss is.

Let us know.

Also, you may want to read this page:
http://www.poolforum.com/pf2/showthread.php?18597 (Adding-Borax-to-Make-your-Pool-Resistant-to-Algae)