Dwight, have you tried more weight on your anchor ropes? We use 40 lb cement blocks on ours and they don't move but our aerators are also a bit different than your's or Bruce's. Also, you will want to have your rope length 3 times the depth the anchors are sitting in. We are using heavy poly rope that floats, two anchors on the front that angle off to the sides and one straight off the back.
PS A 12ft jon boat would save some swimming in that "20 below zero weather."
