WISRD Research & Engineering Journal

2.3 Rack Dimensions We maximized the size of the frag rack to allow it to “lock in” to the substrate in the tank most effectively, thereby minimizing any rotation or shifting. The rack lightly scratches the front and back surfaces of the tank glass as it is inserted, and its weight and open style design allow for it to stay in place. The large rack also allows for multiple pieces of coral frags to be monitored simultaneously. ● Frag rack: 61 cm wide x 44 cm deep ● Internal opening of a single square in the rack: 14.60 mm; external width of a single square: 17.73 mm; width of individual cross members: 1.75 mm. (Figure 5 below.). PVC pipe legs/feet: approximately 63.5 mm in diameter and 25.4 mm wide ● Mini zip ties: 3 x 100 mm long

Figure 5 . Dimensions of individual squares within the frag rack. Left: Internal dimension; Middle: External dimension; Right: Dimension of plastic cross members. 2.4 Rack Construction A 61 cm x 61 cm frag rack was cut to size using a band saw. The PVC legs of the rack were cut to size using a table saw. A miter saw was considered for the PVC, however, the fixed blade of the table saw allowed for more control of the PVC. The cut edges of the PVC were sanded with 100 grit and 400 grit sandpaper as smooth surfaces grow less algae than rough surfaces. Four PVC legs were attached to each corner of the frag rack and one PVC leg was attached in the center via zip ties. The PVC circles originated from a single blue PVC tube. These legs are necessary to elevate the crate off the sand for insertion of ceramic plugs, water circulation, and to level the platform. Key steps in rack construction are shown in Figure 6.

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