Peter we need more info. Do the canals connect with the lake ?

With only 2 people fishing and 40 acres and a year round growing season it will be difficult to remove enough LMB/PB to get where you want.

I suggest you locate a private fisheries scientist with a shock boat. Have them sample the lake to establish what the fish population is and get his recommendation. We can try to help from here but we are just guessing without knowing the forage situation. If you are connected with the canal system it will make a big difference.