I am going to make my own minnow grader to separate different sizes of baitfish . Will be adding dividers into my two tank system to separate bait into at least 3 sizes/species , perhaps 4 sizes/species. I am loosing smaller baitfish to cannabalism over time. I often see larger baitfish in the tanks with a tail hanging out of thier mouths. The following link is to a PDF file which explains the process and has alot of helpful info, including a "grade" size chart for golden shiners and other fish.
http://www.ca.uky.edu/wkrec/391fs.pdf.
My first thought was refigerator or commercial racks with the proper "grade" size cut to fit into plastic tote. Add rubber edges for a tighter flexible fit and tada. But finding multiple sized racks may prove difficult. I have access to Acetylene torches for the cutting, so that part is do-able. I may have an easier route. I may pick up 3 identical totes, so that one will fit inside another. Two of which I will take my trusty dremel tool to, cutting slots to the proper size , being careful to link the slots together at appropriate intervals to prevent the slots from flexing and allowing larger baitfish through. In theory, it sounds like a feasible plan for my small operation. Select a size "grader" tote, dump the 5 gallon buckets of trapped bait into the grader and then pull the inner tote out and dump baitfish into appropriate tank section. Gutta find me some heavy duty totes on sale and implement this theory! Anyone else have a system for separating different sizes of baitfish, other than by hand? Any homemade minnow graders out there?