Re: Weight of 2 gallon feeder buckets.
Biggest draw back with the profeeder that I've found (and this was before the cap and ladder system) was that the feeder itself would warp in warm weather (or just from the heat of the hive) and especially bad when the bees would attach comb to it. The new cap and ladder system makes the feeders top quite a bit stiffer (the cap being the wooden part).
The way the feeder works is you fill up the plastic feeder (which takes up the space of a single frame if you get the 1 gallon feeder, the 1.5 and 2 gallon feeders take up 2 spaces) and the bees enter through the holes in the cap. Inside the cap is a plastic mesh sock that allows the bees to climb down inside the feeder and retrieve the syrup then safely climb back out without any drowning. Last year using the cap and ladder feeders I had ZERO drownings, however, after the feeders were emptied the bees started building comb inside the ladders that I'm going to have to clean out some time this year. Or just fill around it I suppose, the bees are still able to get in and out =P
Aldous Huxley - Facts do not cease to exist because they are ignored.