Trying to design proper support for a long bookshelf aquarium. The aquarium is 72x12x12 approximately 44 gallons. Which equates to about 360lbs of water weight. Since it will also contain rock/coral/sand etc... I figured I'd calculate a load of 700lbs to have a margin of safety. The tank fabricator messed up and ran the drain lines out the back instead of the bottom which pushed me from my original shelf depth of 13-14" up to 17" which adds quite a bit of leverage I think.
The tank is going in an alcove that is 88" wide. My plan was to run the shelf the full 88" and half the back and sides fastened to a cleat(1x4 pine). I was also planning on edging the front with 1x4 pine to help stiffen it. The shelf material itself was originally going to be Advantek subfloor OSB but I think I'll need to beef that up and laminate 1/2" or maybe 3/4" Plywood to it?
Next I was planning on adding 4 or 6 Everbuilt shelf brackets to support it along the wall at the studs. The problem is I don't have much more clearance than for the 8" shelf brackets because the vertical portion for them is 12" which is pretty much all the room I have underneath the proposed shelf. At 1200lbs a pair they can certainly handle the vertical load, but 9" of cantilever seems excessive. The next size up bracket is 20"vertical 13" horizontal. That would drop me down to 4" of cantilever but that is assuming I can manage to fit the longer bracket in.
Lastly I was planning on gluing a piece of oak trim on the front to cover the shelf edge, and cleat ends. Essentially double edging the shelf.
I considered adding support to the underside of the shelf by gluing 1x4 pieces running on edge from the back to the front of the shelf(basically mini floor joists if you will). Just not sure how to calculate there value and if it sufficient to allow me to use the shorter(12x8) brackets.
Any thoughts/suggestions on how to properly support this would be greatly appreciated.