R..sedge - Since you are from IL do not expect your fish to grow very much if at all in the time period from fall to April. By "stocking in Fall", I assume your fingerlings were stocked in late Sept - October or early Nov. In your latitude (plant growing zone) there are very few growing days from Fall to April where water temps are above 55-60F. The fish you are talking about are bascially warm water fish and growth is good to best at water temps above 65F. This is especially true for the redear sunfish which are native to warmer areas of the country so growth is best above 70F. You should see noticable improvement in these fish by fall this year unless they are too crowded and or they have too much competition in your pond.
Bullheads. Try baiting your fish-bullhead traps with dead fish or cat, dog or fish food. The odors attract the bulheads.
