A refugium is nothing more than a refuge from predation. Sessile inverts, macroalgae and other delicate species need a place to call their own and the advent of the refugium was just the ticket! Isolated, but connected to the main display tank, the refugium allows for common water filtration while at the same time keeping more aggressive fish from impacting it. Refugiums have been found to be an excellent platform for cultivating food sources (amphipods, copepods and macroalgae) in a separate but still attached system.
Types of RefugiumsThere are 3 types of refugiums: Hang-In-Tank, Hang-On-Tank and Sump (Under-Tank) style refugiums. Each type of refugium has its own pros and cons.
Hang-In-Tank Refugium Pros & Cons
- Pros: Doesn't require more room than you are already using for your tank; expensive refugium to install; easy to see what is in the refugium; uses existing tank lighting for macroalgae cultivation.
- Cons: Can look sort of weird in the tank; doesn't add water volume to your aquarium system, limits timing of light schedule to that of your main aquarium.
As it describes, Hang-On-Tank Refugiums hang on the tank (usually on the back of the tank, although you can install it on the sides or front, if you wish).Hang-On-Tank Refugium Pros & Cons
- Pros: Shares water with your main tank, which is essential if your are cultivating macroalgae to reduce nitrates and phosphates; doesn't "clutter your tank" like a hang-in-tank refugium does.
- Cons: May require an additional light source; may be difficult to install behind your tank (due to wall clearance); may be difficult to clean due to position behind that tank.
Sump (Under-Tank) Refugiums
Sump (Under-Tank) Refugium Pros & Cons ;
- Pros: Excellent platform for protein skimmers and other pieces of equipment; even if your tank isn't drilled, they can be fed from your main tank with an Overflow Box Kit add to total tank water volume; least expensive style refugium per water volume if Cheap, Easy DIY Sump is utilized; relatively inexpensive LED lighting fixtures work well with sump refugiums; plenty of room for growing Red and Green macroalgae.
- Cons: Requires a separate light source; can be relatively expensive if a complete refugium system, with return pump and protein skimmer are included (see Top Refugiums for Saltwater Aquariums