You won't need all of that muriatic acid. Maybe a cup or two at most. You just want to bring the ph down to 7.5, the alkalinity if fine, and the calcium is fine for a vinyl liner pool. You will need a lot of bleach to keep the chlorine level at shock, which will be different according to how much cya is in the water. Ususally with a salt water generator they want the cya ato 60 or above, so I would make sure I get a cya reading fast, so you know how much chlorine to keep in there to clear up the algae. Do not turn on the salt genterator till the algae is cleared up - no use in running it if you have to be adding chlorine all the time anyway. Make sure you check the chlorine level at night and in the morning, this way you can see if the free chlorine is holding overnight. I really think a good test kit is the most important tool you can have when you have a pool. When you have a high chlorine level in the water, the ph test may be off, so worry more about having the chlorine in than anything else right now. Here is the best guess chart:

Use the info in this chart to help you figure out what levels of chlorine you need to maintain in your pool based on the amount of CYA (cyanuric acid, also called stabilizer) that you have in your pool. (FC = free chlorine)

Stabilizer . . . . . . Min. FC . . . . Max FC . . . 'Shock' FC
=> 0 ppm . . . . . . . 1 ppm . . . . . 3 ppm . . . . 10 ppm
=> 10 - 20 ppm . . . . 2 ppm . . . . . 5 ppm . . . . 12 ppm
=> 30 - 50 ppm . . . . 3 ppm . . . . . 6 ppm . . . . 15 ppm
=> 60 - 90 ppm . . . . 5 ppm . . . . . 10 ppm . . .. 20 ppm
=> 100 - 200 ppm . . . 8 ppm . . . . . 15 ppm . . .. 25 ppm

Let us know if you have any other questions