I am getting ready to add water to my new pond and need to add some structure first. The pond will be stocked with LMB. BG, RES, and CC. I planned to buy 100 of the 8" cinder/ concrete blocks and make 2-3 jumbled rock piles in the pond. Do I have to worry about the CC pawning in the concrete block cavities? The pond will average 12' indepth and the deepest part will be about 14'.