Ok. You need the dichlor ASAP. Your pool is large enough, so that if you can get it at Sams Club, you may want the 50# bucket instead of the 24 1lb bags.

Meanwhile, add 2 gallons of PLAIN 6% household bleach (4 ppm of chlorine) to your pool each evening. 1 gallon of *fresh* liquid chlorine is an OK replacement.

Plain dichlor is hard to find locally, but stabilizer (cyanuric acid) is sometimes available. If you can find some, put 4 lbs or so in an old athletic sock, and put it in the skimmer. You do NOT want the CYA granules in the folds of your System 3 beast cartridge!

List what chemicals you have on hand, if any, so we can see what you can go ahead and use up.