I'm scheduled to get a doughboy Autumn Breeze 41x21 installed. The documentation I've found from Doughboy on below grade installation seems a little unclear on whether I need a slurry mix. My soil is very rocky and loaded with thick clay. I'll also have the 7ft deep end. I see where they recommend slurry for decking or concrete but I don't plan on either going right up to the pool. Also, because I have a pond about 50 feet behind my property, I wonder if a sump pump is necessary. Does anyone else here have a similar setup, soil-wise?