A newly completed rack

This new design is as simple and efficient as possible.  It is built on the Costco Racking, with MacCourt Super tubs.  The tubs are 36x24x8 made of molded polyethylene, by MacCourt here in the USA.  They are available through Ace hardware and sometimes Lowes.  They are much sturdier than the PVC utility tubs made in Israel, sold by Home depot.   They are very sturdy and with just a few lath strips can overhang the rack a bit, allowing for three tubs per rack instead of just two per shelf.

The tubs are very simple to drill and drains are via one inch bulkheads.  The Rack is topped with a 135 gallon acrylic aquarium and is plumbed to the central filtration system.

The best small tub: MacCourt Super Tub

This is the best inexpensive tub that will fit my 6 x 2 foot costco racks 36 x 24 x 8 inches 23 gallons.  The local hardware stores sells them for $14.  They are heavy duty HDPE or similar plastic and are much stronger than the pvc tubs sold for a similar price at Home depot. The are stocked at ACE hardware stores.  The ridges add to their strength but unfortunately the ridges in the bottom interfere with my preferred bulkhead placement but I can work around that.  

SUPER TUB
(ST3608)
36" x 24" x 8"
23 gallon capacity
3.2 cu. ft. capacity

http://www.maccourt.com/products/ponds/st3608.html