I have a buddy that uses a Styrofoam top feeder. On one side it has a clear plastic "L" shaped cover that runs vertically, down to the liquid. This forms the channel the the bees travel to get to the sugar water. The feeder must hold a good 3 + gallons of fluid or better. Unlike my top feeder, his Styrofoam feeder works extremely well. Few, if any drown bees. The feeder is Styrofoam so the sugar water seems to store quite well. It's pretty expensive, which is the down side. If it was 1/3 of the current price, I'd certainly buy several.