Did you know that macroalgae isn’t the only beneficial thing that can be grown in a refugium? While most refugia do are limited to just macroalgae and random invertebrate crustaceans, they can also be a home for filter feeding corals and inverts. For example, some aquarium keepers use Xenia corals instead of macroalgae, typically culling the population when it gets too large. Tridacnid clams can also be used as a filtering invertebrate. Just cram a whole bunch into your refugium and they’ll constantly take in nitrate. If neither of those work for you, sponges can also be used, and some may even pop up on their own in any low light areas of the sump. So, when stocking your refugium, don’t always limit yourself to macroalgae. Sure, they work great, but they’re in no way cooler than a clam refuge.