Pictures of my Refugium

A refugium is a body of water that's physically separated from the main aquarium, but shares a common water supply with it. The purpose of a refugium is to provide a refuge for animals and algae that suffer from excess predation in the main display tank. The effect is to increase the diversity of the whole system beyond that possible with a single tank of similar size. My refugium is a standard 20 gallon high aquarium. This is half the size of the main aquarium, at 40 gallons. It's located above the main aquarium. Water is pumped into the refugium from the sump below the main aquarium, and overflow from the refugium flows directly into the main tank, with no intervening pumps. One specific goal I have for the refugium is to generate a supply of live copepods to act as food for my mandarin dragonets in the main aquarium. The hope is that the fishless refugium will be able to maintain a higher breeding population of copepods than the main tank will, and then the larvae (and some of the adults) will occasionally find their way down to the main aquarium. In general however, I just want to see what happens.

My refugium contains 30 pounds of Tropico Reeflife's live sand, and about 50 pounds of their live rock. This rock is a mixture of the coralline grade rock and premium rock from Tropico Reeflife.

Between September 1995 and May 1996, the tank was lit by just two 24", 20 watt fluorescent bulbs. That's rather low light for a reef, but coralline algae showed no signs of dying, and even showed some growth. In mid May 1996, I replaced the fluorescent lighting with a single bulb. It's a 400 watt, 10,000K metal halide bulb made by Coralife. The tank looks a lot better with the new light, but will the life in it handle the light okay?