Never thought about throwing a net for minnows in the lake. My cast net is 8' 1/2" mesh so it would be a waste of time.
You might try throwing the net then jerking it up fast. I cast for Shad in 90" of water I had to throw an jerk to keep the bait from going deep. 1-15' Of water I just let it go to the bottom and pull it up
Not much help but my 2 cents