Plugging holes (turning a reef tank into a freshwater

[CHOMPERS]

It does not include filtration system or lamps for the light fixtures. It was origally set up for a custom, closed loop filtration system (which is I guess why there are holes in the back)

Yes, large reef tanks can be plumbed with closed loop "pulse" systems to simulate currents like on a natural reef. The systems diverter manifold looks like an irrigation "octopus" (manifold). That is why there are so many holes in the back.

For future reference, the lights in the hood are Metal Halide lamps. The fluorescent bulbs should be blue actinic bulbs for coral growth.