We have just finished the install of our pool. We have a vermiculite bottom pool with a liner. Our pool is fairly good sized at 20x50 and 10 ft deep at the deep end. I know that vermiculite is supposed to be 'soft', but I have noticed that some of the minor 'imperfections' on the bottom of the deep end have turned into fairly noticeable divots especially with the light on at night. Are the divots to be expected, or do we have another problem?