That makes much, much more sense. Now...did you fill your pool from a well (checking to make sure there's no iron in the water) or from city water?

If you filled from a well, that's a whole 'nother ball game, so disregard what's below for now. If you didn't......

You need to shock the pool by bringing your chlorine level up to 15 ppm. In a 20K gallon pool, each 1.5 gallons of 6% bleach will raise your chlorine by 4.5 ppm. Each 1.5 quarts will raise your FC by just over 1 ppm. You're shocking in order to burn off that CC, which is an indication that the chlorine in your water is fighting something, probably algae. Once you're at 15 ppm, then you need to test and add more bleach as many times as possible during the day until you can test at night and again in the morning before the sun is on the pool, and not lose any chlorine. At that point, you can let the chlorine drift back down to the 3-6 ppm range, but never let it get below 3 ppm. Keep the pump running 24/7 during the process, backwashing your filter as needed.

BTW, need to fix the volume in your signature--I'm assuming it's 20,000 gallons and not 2000....