Snipe,
The clearing of your water is a sign that you are making progress
It's great that you have doing measurements of your crawdad catch and sharing with us here. That's a remarkable weight of them from a 3/4 acre pond (322 lbs/acre) so far. Its remarkable for a number of reasons but particularly because that the weight is high proportion of what the pond could carry ... even without fish. Northerns can reach >3" by the end of their first summer, so these are at least a year old.
Given the proportion of smaller ones in the creel survey (20 lbs released to 242 lbs harvested), I think that you have a strong year class and that the presence of so many large crawdads has prevented good recruitment of smaller ones in this growing season. What you want of course is the opposite where there is a modest population of adults and a bumper crop of juveniles. In any event, the management you are doing is spot on. Going forward you should be able to control them with a Fall harvest annually. So next year if you don't catch a lot of adults in the fall, then the fish are letting fewer crawdads make it to adulthood and the YOY crawdads are being utilized by your fish.
