Thank you for your resposes.
RE: material to go under the tank, I contacted the manufacturer last night and he recommended 1" ply... much easier to slide the tank over than synthetic rubber was his view... I can't argue with that.
RE: circulation, Ellot, your suggestion is sound, but I just can't get past the fact that cetrifugal pumps are optmised more for pressure than flow... lets take an example. If I want to move 30 x 2300G, I need 69,000 GPH. If i were to use 5 out 1 in eductors, this means I need 69,000 / 5 = 13,800 GPH (230 GPM) from the pump at ~20' head pressure to get the eductors to work properly. Looking up a couple of pump curve books, I see that I can get this by using 2 x 1.5HP pumps (2.2kW in total). Using 2 ring thrusters, I can move 40x for 200W. Using a VFD to slow down the motor will save power (e.g. 1/2 speed = 1/8 power) but would also significantly reduce pressure, diminishing the effectiveness of the eductors.
Jonathan, thank for your thought provoking comments. I will probably not cover the whole stand in epoxy, but your comments have promped me to more carefully consider salt water management with respect to the stand (specifically, plumbing will come out of one end of the aquarium only... I will glue on some acrylic to the bottom side of the tank to prevent water from flowing back under the stand. I will then epoxy the immediate area.)
The ring thruster is made by a company called
Klingenburg
Brax thanks for your comments too. I have now considered single point of failure.
How about this set-up (2 ring thrusters to go in the holes in the blue acrylic pannel:
Two ring thrusters tangential to tank wall should cause a flow pattern as per bottom picture. The blue acrylic is purely to guide flow. The square is the overflow box that will host standpipes.
From an aquascape perspective comming straight out from the blue acrylic will be the "reef flat area", so the bottom slot will be hidden.
