Ahh, the refugium. A staple of the American marine aquarium. These interesting tanks beneath the aquarium are the source of a lot of debate, but in our opinions, their benefits outweigh their drawbacks. Their drawbacks you ask? Well, many feel that they are unnecessary, ineffective, and just another item for an aquarist to buy. While we certainly see the merit of that argument, the benefits of pH stabilization, nutrient export, and a place to house beneficial invertebrates are far greater. Sure, having a refugium is expensive, and their effectiveness as nutrient exporters is variable and depends on both their size and the constant need to prune macroalgae, but they work and add an another area of amazement and wonder to your setup. I can’t tell you how many times I’ve found myself staring at ‘pods dancing around in the sand or bristleworms crawling around on the rocks.