the amount of salt required depends on how much water is in the pool
You will need enough salt to reach a concentration of 4000 ppm (parts per million) to start. Have the water tested for salt content at your pool shop (usualy free), then add then add enough to reach 4000 ppm.
Not likely
30 feet!
Little
28 or 30 mil
we can not tll yo because you have not told us what it is made of and how wide and deep it is.
2100 gals
Assuming that you're referring to a cylindrical pool that has a 30 foot diameter and is evenly 10 feet deep throughout, it should hold approximately 940 gallons of water.
A pool that is 15 feet x 30 feet with the average depth of 6 feet is approximately 25,000 gallons.
Circumfence 2 x 15 x pi = 94 feet 3 inches
It depends how many gallons your pool is. Once you buy your chlorinating system, the install manual will tell you how much salt to add based on how many gallons in the pool. I have an Autopilot Digital and it tells me when it needs salt. I still check it with test strips to be safe.
This depends on the concentration of this salt water.