One thing to remember is that using rubbermaid tubs for a reservoir, you may find you need to support the tub in some way, such as an exoskeleton of 2x4s bolted together, so it does not collapse under the weight of the water. Once you get into large volumes this becomes a problem.
I actually stopped by Zellers (canadian walmart) store yesterday to source some potential reservoirs. Rubbermaid has a RoughNeck 38.6 x 21.2 x 18.6 in container (i figured it out to be approx. 62 gal) then i was hoping feed a 3 x 2 table top of 6" net pots. Problem is, i plan to grow in my room (attic floor) and don't want to haul multiple 5 gal pails of fresh water up steep steps every week if i don't have to. Having not even though of the containers structural integrity with the weight of the water, potential leaks or ruptures really concern me.

i know dwc is not your forte, but what do you think if i tried two sets of black 18 gal containers (23 1/2" x 17 3/4" x 15 1/2") with 4 x 6inch net pots. Would water weight still be an issue in these sized containers?