To ensure adequate access to the display tank, the light hood assembly is mounted on a suspended, sliding rail system. This arrangement further enables complete access to every inch of the display tank without having to employ special tools. The sliding rails, and associated hardware, for the suspended light hood are made by Stanley Hardware and are conventionally used for hanging barn doors.
The hood itself is constructed from a 2 X 4 wood frame that is sheeted in ¾” particle board. All the exposed wood surfaces were then covered with white Formica to provide a durable and cleanable surface.
To minimize the number of electrical cords that must accommodate the sliding motion, all of the ballasts ride on top of the hood. The electrical power to the light hood is supplied by four 20 amp circuits that are located on the ceiling above the light hood. The 5800 watts of lighting consists of:
(12) 400 watt metal halide bulbs in Reef Optix reflectors
(6) 165 watt VHO actinic bulbs on Ice Cap 430 ballasts
(3) pulse start dual ballasts
(3) HQI dual ballasts
The actual bulb mix is something that is changed to spotlight certain areas that sometimes might need a little more blue or a little more white. As the aquascaping evolves, these changes will become more permanent. Currently, I’m using:
(6) 165 watt actinic VHO bulbs
(4) 400 watt 14K Aqua Connect MH bulbs
(3) 400 watt 10K Ushio bulbs
(5) 400 watt Radium bulbs
I can further tweak the lighting by choosing which bulb gets driven on which ballast. Since all the ballasts ride on top of the sliding light hood, switching ballasts around is easily accomplished.
The layout of the lights themselves is chosen to correspond with the tank’s openings. No metal halide bulb shines directly down onto the acrylic….. and no metal halide bulb shines down into the overflows. The bulb layout also is positioned away from the sides of the display tank to visually dim these areas…. which draws the viewer’s eye back towards the center.
In other words, I light the areas that I want to emphasize and darken the areas that I want to de-emphasize.
Twelve 4” cooling fans were installed to provide ventilation for the hood with four fans located on each of the three available sides.
The four fans on the back of the hood pull air out while the remaining eight fans push air into the hood.