The refugium is touted as being able to do everything ranging from feeding the fish to negating need for changing water in the aquarium and much more. Unfortunately, most aquarists don’t really understand them and thus end up misusing refugia and expecting them to do things they weren’t designed for. You can use refugium for growing live foods for your fish. Depending on what you have in your aquarium, they are used for growing different types of foods like algae and plankton and much more. Also, refugium helps in reduction of levels of nitrate in the aquarium. Keep in mind that they reduce nitrates but you still need to do water chages.
Simply put in layman’s language, refugium is simply a refuge place. What you use it for majorly depends on the nature of your aquarium as well as your interests. However, typical residents tend to include macro algae, feather duster worms and even copepods. Whatever you add in your refugia will simply depend on what your favorites are. The refugium is usually an appendage to the marine tank and shares the same supply of water. Some applications tend to limit flow of water as a way of protecting animals and plants which need slow glow.
The light cycle of the refugium may at times be operated on the opposite of the main tank and helps ensure that the PH of the system is stable. During the daylight hours, the refugium takes up the CO2 that forms the acid. The main purposes of a refugium include de-nitrification, production of plankton, nutrient export, surface agitation, circulation, and aesthetic or oxygenation purposes. When constructing a refugium, keep in mind that a tropical marine refugium tends to contain live sand and live rock, macro algae and even scavenger microfauna like micro brittle stars, worms and snails.
If you decide not to buy your refugium from the store, you have so many options available to you when it comes to DIY construction. You can use downstream or upstream processes for connecting water flow into your refugium. When designed properly, the refugium works greatly as a biological filter and are wonderful natural filters necessitating their increased use in most aquariums. They filter water in numerous ways and thus helps ensure that your aquarium is at its best shape always.