If youve got access to a small dozer or tractor, now might be a good time to consider cleaning out the muck on the bottom and repacking your sand/clay. Don't think you'd need bentonite at all if your true bottom is sealed good. All that muck is gonna be holding some serious nutrients and when your water comes back you may have other issues to deal with. Just my $.02 and definitely not worth that!!

.10 surface acre pond, 10.5 foot deep. SW LA. The epitome of a mutt pond. BG, LMB, GSF, RES, BH, Warmouth, Longear Sunfish, Gambusia,Mud Minnows, Crappie, and now shiners!!...I subscribe!!