I've been sitting on these tanks for almost a year now so I'm going to do my best to get this project going over Christmas. I'll start with a few pictures to give everyone an idea of what I'm building then back up a bit to the planning stage.
The first step is drilling the tanks, I lined up the holes using a paper template since it doesn't need to be super precise.
I used some sticky-tac to hold a small pool of water around the hole. I've never drilled glass before but it was very easy.
Just remember to put something under the hole to catch the waste disk or will fall and scratch the other side of the tank. I cut a total of nine holes in three tanks.
Next I cut a few cork rectangles to support the tanks. This only takes a few seconds if you trim around the edges of the tank.
Finally I applied backing film to the tanks. Although the process is straightforward I found it incredibly difficult to get a perfect application.
Lay the film on top of a wet surface and then squeegee any bubbles to the edge. I tried to push everything downwards so any trapped dust would be hidden by substrate.
Finally trim the edge (and holes) with a knife.
Black is done the same way.
I use two layers of the black film since it is slightly translucent otherwise. The second layer looks a little bumpy but its fine from the glass side.
And finally a peek at the goal of this project.
I've always wanted a tower of nano aquariums - I like the idea of having multiple small tanks, and the design is very space efficient. On the other hand, individually equipping and maintaining four separate tanks would be rather inconvenient. To work around this I've decided to connect them together. This will provide the convenience and stability of a larger tank and can reduce some costs by sharing CO2, filtration, and heat.
The bookshelf will hold four Mr. Aqua 6g aquariums (24"l x 6.4"d x 9.7"h). The top three tanks will be used for display and contain no equipment other than an overflow and return. The fourth tank will be used as a sump, but only 8" of its total length is required to house equipment; the remaining 16" will be lit and used as a display area. The sump will only hold a few inches of water in use so most growth will be high humidity/emmersed.
There are two major risks with this build. The first and most catastrophic scenario would be failure of the bookshelf. I consider this low probability, but it would be extremely costly which does make me nervous. Although aquariums are typically too heavy for standard furniture, six gallons is small and a full 30" shelf of books has roughly the same weight. This setup will fully load only three of the five shelves, so the bookshelf should actually be supporting less weight than it otherwise would.
The second risk is that the overflow system will be too noisy. My plan is to tee three silent herbie systems into the same drain/emergency lines - I'm pretty sure this will work, but most plumbing guides contain fairly insistent warnings that tees in the return line are discouraged.
I'll try to finish most of the build before new years but some of the parts have had their delivery dates pushed back by Christmas shipping.
And yes, I am aware this is a very complex way of setting up 18g of display space.