I've got to add about 25 pounds of Calcium Chloride to my plaster pool. The "pool school" section says to spread it around the deep end of the pool. But I've also read on here that some people suggest dissolving it in a bucket of pool water then slowly pouring it in. Is there a preferred method? I'm a little hesitant to let that stuff sit on the bottom of my pool for a couple of hours until it dissolves. And should I do all 25 lbs at once or half one day, and half the next?