I'm assuming you mean that you went to Sams Club, and bought their dichlor?

If so, start dosing your pool with dichlor at the rate of 1/3 lb or 3/4 cup, per dose. Make sure NOTHING is in your skimmer or feeder -- no tabs, pills, gizzmos, etc -- and then add the dichlor directly to the skimmer, while the pump is running. Make sure the pump runs for at least 1/2 hour after each dose.

You can add multiple doses in one day, but space them out. Adding too much at once is more likely to result in any remaining copper turning into stains!

Once you've added a total of 4 lbs, you'll have about 20 - 25ppm of stabilizer, and should begin to see your chlorine last longer. Here's how to track your stabilizer level:
Lbs added = CYA ppm
4 -----------> 24
8 -----------> 48
12 ----------> 72
(for ~10,000 gallon pool)

Evaporation won't lower your CYA, but splash out and leaks will. However, before you get to 10 lbs of added dichlor, let's work out an over all treatment plan for your pool. OK?

Meanwhile, read the Best Guess page linked in my signature, so you kinda get to understanding it, before you have to do so.