When I started I dumped half of my water. From 48" deep down to 24". Keep at least 12" of water in.
Use
PoolMath fill it out for gallons in the estimating pool volume. Scroll down past the Pool Math Stuff and get your gallons. Put that in at the top of the page. Then put your current numbers from you own test kit in the NOW column. Tell Pool Math what you want your numbers to be in the Target column. It will tell you what to do.