I need to add approximately 35 pounds of CH increaser to my pool. My level is currently 100 and the manufacturer of my fiberglass pool recommends a level of 300. I took a sample of my water into a local pool store so I could make sure I tested my water correctly, and they told me to add 35 pounds of CH increaser, in 8-9 pound increments. I get the same figure when I plug my test results into the Pool Math Calculator so I assume this is accurate. The lady at the pool store said to put the CH into a pillow case each time I add it, and tie the pillow case to the ladder because the CH increaser can harm the floor of my pool because it gets hot when added to water. This sounds crazy to me and contradicts what is taught on here, so I assume that I need to broadcast it around the deep end instead. Since I need to add 35 pounds of it, how many pounds should I add at one time, and how long do I need to run the pump afterwards before I shut the pump off or add more of it to my pool? I know from experience that it gets hot when you add it to a bucket of water, so I assume that it is important to brush well after broadcasting it. I don't want to do anything that could potentially harm the floor of my fiberglass pool so I wanted to make sure I understand how to add it before I do anything.