Building shelving for this and my last coral farm was what I felt to be an evolutionary step with regards to care and productivity. Previous to having employed any organizational methods, I merely grew on rose bud vases, also called floral picks. I just wedged a fragmented coral in the opening and plopped the pick in the sand.
There was never a way to keep the picks neatly spaced and each week a few were knocked down, for some reason or another. Another problem with the picks was that positioning them in the sand bed meant they needed to be at the bottom of the tank. I had made a few advancements on the picks before I abandoned them.
The best was building shelves out of Plexiglas and bedding them in with a heat gun in the shape of a flattened C. I then drilled the center segment with a series of holes, each large enough for a floral
pick. This method worked for a while, but the shelves were flimsy and did not offer much support. Later I moved to plastic sandwich containers, the kind you find at a deli. I would fill the trays with crushed coral and grew the frags on small pieces of rubble.
To date this was certainly the most promising, but it to needed some refinement. The crushed coral was getting to be messy and always a maintenance issue trapping detritus and what not, creating an algae magnet. I changed to aragonite sand in the containers, and moved from floral picks to GARF plugs. The plugs were much more stable and more natural than the picks, plus they blended in nicely with rock in the reef aquarium. GARF sells the plugs very inexpensively plus they share the steps for all of you do it yourselfers. I think just a few dollars in supplies will make about 400 plugs. I stuck with this method for some time until I felt I could do a bit better.
What I was striving for was a uniform shelving system that had a predetermined amount of spaces in it to grow corals. In addition, by moving to something a bit sturdier would permit greater water flow. Working with the trays eventually becomes time consuming. Undesirable algae would populate the plastic and the sand in the trays would always spill out. In time the trays themselves cracked requiring more work to repair.