OK. I got my second diffuser installed. The water is a good looking green and all of the smell is gone. Most all of the black crud is gone. I have tried fishing and and trapping and still haven't seen any indications of life, other than thousands of bullfrog tadpoles. Other than doing a shock survey what is the best way to find out if anything survived. If indeed there is nothing left should I wait until fall to restock with something?