I agree, something's not right with that level of scaling. Perhaps really high pH and really high calcium? In any event, to switch to regular chlorination, all you have to do is start dosing chlorine. I don't think you'll know how much to add on a regular basis until you get a feel for it.

Use the traditional method. Identify your target chlorine level based on your CYA reading and the best guess chart. Then dose chlorine accordingly. Take regular chlorine readings and re dose as needed.

With a 50 cya you want to be between 3-6ppm FC. It takes a little less than a quart of 6% bleach to give you 1% raise in FC in that much water.

You've almost certainly got some other problem leading to the severe scaling though, I'm sure it will manifest its-self in other ways if you don't find and correct that problem.