What is buffer? You need to shock your pool up to about 10 and try and hold it there without letting the cl level bounce up and down. Just use bleach instead of shock - which I assume is either powdered dichlor or cal-hypo. In a pool this size, each quart of 6% bleach should raise your cl level by approximately 1pm. Test 2 or better yet 3x a day and each time raise the cl back up. Run your pump 24/7.

After your water clears, buy some cyanuric acid. (It is also called stabilizer or conditioner.) Add enough to the skimmer while the pump is running to get to an initial dose of about 30ppm. Then, don't retest for it, add more or backwash for about a week to let it dissolve. After you start to get a cya reading, you'll be able to just test and dose with bleach once a day - in the evenings. However, in the meantime, it is going to be necessary to test several times a day. You'll also need to add a little muriatic acid to lower your ph to about 7.4 - 7.6. Add only about a pint at a time slowly in front of a return jet. Be careful not to breathe the fumes or splash it on you. After several hours, retest and redose as needed.

Don't add anything else to your pool. This should help your water clear up. Hope this helps.