I decided to consolidate my tanks of like purpose and parameters and eliminate individual fllters to make maintenance easier and to work with a larger, more stable body of water across several tanks.
I picked up a used sump
Rack will be a 3' wide x 16" deep HDX rack from Home Depot. All tanks are CAD Lights ZEN nano tanks, 7G, 5G and 3G
Water will be pulled from tanks using a DIY overflow like this
I think 1/2" PVC is pretty large for my small tanks so I plan to use either 1/2" or 3/4" PEX tubing from Home Depot
Water will be delivered back to the tanks using U-tube returns like this one connected to PVC tubing
I am now designing my rack system, plumbing circuits and flow requirements. I am planning on 2 shelves, so I was thinking of 2 pumps, one per shelf to make maintenance easier. I am considering http://www.amazon.com/gp/product/B000256ENK/ref=ox_sc_act_title_2?ie=UTF8&psc=1&smid=ATVPDKIKX0DER which will move 200gph at 8' head height though I won't go that high, a ball valve will be installed on each pump to master-limit flow and individual ball valves on each tank return to trim and fine-tune flow per each tank's needs.
Suction clamps will secure tubes and fixtures to the tanks to keep things flexible vs. making rigid PVC pipes to each tank like the LFS has. I will probably route one manifold to each shelf and thread hose adapters into the manifolds allowing a flex hose to each tank. More on this later or please advise.
Lighting will be installed above each shelf, suspended from shelf above, and these will all be low light tanks so I was thinking of these http://www.amazon.com/gp/product/B0045LAS3O/ref=ox_sc_act_title_4?ie=UTF8&psc=1&smid=A2L77EE7U53NWQ to keep cost and profile of the lights low.
Basic rack layout will have tanks installed lengthwise, meaning perpendicular to the shelf, so I can fit more tanks per shelf.
Top Shelf: Light weight storage, really just to suspend light from.
Third Shelf: 3 x 3G tanks (12" x 7" x 8"H) with room for a fourth and fith
Second Shelf: 2 x 5G tanks (14" x 8" x 9"H) with room for a third and fourth
First Shelf: 2 x 7G tanks (16" x 10" x 10"H) with room for a third
Lowest Shelf: SUMP (24"W x 14"D x 14"H)
Rack will be secured to the wall at the top and bottom to keep it square and stable. It will be on concrete so I am not concerned about weight on the floor. But the weight of the tanks is a concern at 10# per gallon of water. There will be minimal hardscape in these tanks so that is not a factor.
The rack is rated to hold 1750# but I will have far less than that, I calculate the following
3G shelf (assuming 5 tanks) 150#
5G shelf = (assuming 4 tanks) 200#
7G shelf = (assuming 3 tanks) 210#
Sump = 200#
Total weight is less than 800#
I will update the thread as I go but the obvious questions are:
1) pump size and flow rate needed
2) size of PVC tubing for output to tanks, per shelf
3) any suggestions re equipment listed so far (pump, lights, etc)
I will be building this in my garage to test all aspects before setting up at home so I have time to work things out.
I'd love to hear from anyone with experience building this setup, or who owns a setup like this. I am sure there are plenty of things I have not considered and I don't want to find out the hard way.