Aquarium refugium is a small aquarium that physically separated from your main aquarium.

It is separated but shares the same water supply from the entire set up.

They are easy to install and can be set up under a saltwater or reef aquarium. It can also hang onto your display aquarium.

There are a growing number of hobbyists that use them nowadays. But there is really no hard and fast rules for setting up a refugium.

I read once in a saltwater aquarium forum that adding a refugium lowers nitrate levels and that’s why they added it in their set up. An explanation to that is because using a refugium actually filters the water naturally. It will then dramatically lower nitrate and phosphate levels of the water.

Aquarium Refugium

Another article I read mentioned that their main purpose of setting up a refugium is to generate a supply of live copepods to act as food for his mandarin dragonets in the main aquarium.

Whatever purpose you may have on setting up one, here are a couple of list of the benefits of having one.

  • It provides shelter or protection from danger, hence the word “refuge”, for inhabitants and algae that is in danger from predation in the main aquarium.
    Sessile inverts and other delicate species need a place to call their own and the advent of the refugium was just the ticket!

    The focus here is to provide a “quiet” zone for Seahorses, Peppermint Shrimps, Copepods & Amphipods and other denizens that would otherwise not last long at all in a community tank.

    While benefiting from the improved water quality that most reef systems provide, this isolation allows for spawning in our shrimps or other animals, as well as providing a nice sand bed for beneficial worms and other sifters.

    – by Don Carner, Source:


  • It also provides your existing aquarium inhabitants with natural food sources. The uneaten food are usually trapped in mechanical filters. Having a saltwater aquarium refugium makes this detritus and uneaten food settle within the rock and deep sand of the refugium.

    Microcrustaceans such as amphipods and copepods will feed on it once it’s transported. Since there are no fish in the refugium, the microcrustaceans multiply. And whola!! Your result – natural food source biodiversity to the aquarium!

  • Another benefit is it helps control algae growth in the existing aquarium. This goes hand in hand in lowering nitrate and phosphate level in your saltwater aquarium.

    In the refugium, you deliberately grow algae under bright lights. This removes a lot of the nitrate and other nutrients from the water, so there is less available for the stray algae in the tank to use. When you remove the excess algae from the refugium you are actually removing waste nutrients from the system.

And… to summarize all these, aquarium refugiums offer an ideal natural solution for enhancing and maintaining healthy conditions in a marine hobbyists’ aquarium.


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