I have a small approx. 200 gallon pond. Currently in it there are 7 small frogs and various water bugs. The water is clear due to the chara in it. Being only 1ft deep I know it is a long shot to get it to stay open in winter but how could I? Also how would I aerate it? I put an aquarium filter in but that was far from perfect. I can obtain all the fish from my 1/2 acre pond but I won't put anything in until I know it will live the year.