Refugium: What IS....? How To....?


Ok, I am reading posts that mention refugiums in place of sumps and wet dry filters. Please explain to me without using too many abreviations what a refugium is used for, what it consists of, and how one might go about building one. If there are any benefits to a refugium over using a standard powerfilter and skimmer hanging off the back of my 55gal tank.


At its most fundamental level, a refugium is nothing more than a safe place where some livestock can grow free from the reach of its would-be predators. It can be a section of an aquarium separated by a simple divider, a drop-in in-tank refugium, a section of a sump or a separate tank tied into the main system. The purpose of the refugium in an aquarium is to allow certain species to grow or reproduce.
While this basic concept is implemented in all refugia, most have developed to serve more functions. While specific refugium functions are many -- including denitrification, nutrient absorption, algae cultivation, invert cultivation, coral propagation, alkalinity buffering, ph control, calcium supplementation and detritus filtration -- most refugia are designed with one of two (or both) functions in mind: filtration or feeding.
You can build one out of a spare tank or one bought just for this, any size you want. Bang Guy has a 900 gallon fuge that he calls a lagoon. (barbie sold seperatly)
Plumbing it depends on how you want to set it up. As part of the main display, hidden away underneath, above your aquarium, in a seperate room, hang on back, many possibilities.
By placing macro algea inside you can have your nitrate reduction as well as a DSB for further NO3 reduction. Using partitions you can place your pump inside to return to the main and keep your pump out of the sandbed or macro algea's. If succesful enough you may no longer need a skimmer or other machanical filtrations.


zibnata, thanks for the link. I read that article before I posted my question. Most talk in the threads refer to a refug as a filtration device, not as a refuge.
Thomas712, Thanks for the info. I would like to know the ratio sizes, and how exactly to set one up: what it needs in it to create a filtration system.
Thanks all.


a size of fuge to tank baseline is hard to come up with. it depends largely on how much macro algae you can cram into it. generally, a fuge will allow you to grow frags, hold delicate fish, grow pods... all the things thomas suggested. the best way to put it would be to make the largest fuge you can to fit in the area it is going to go. this also gives you increased water volume to your system, thereby increasing stability.
my fuge currently is about 10 gallons on a 29 gallon tank. my skimmer no longer skims much at all, so i would say that i could most likely take my skimmer offline. at times of heavy feedings, or when corals spawn, my skimmer still produces good foam though, so i keep it running. if you set up your fuge and your skimmer no longer produces foam, you could make the call then whether or not you wanted to remove it from your system.
a 55 is tricky as it is as narrow as tanks generally go. basically anything you can fit under your tank will produce positive results for you. in bang guys case he has all the space he could ever use as his filtration is remote from his tank. i would say if you wanted a number to run with, i would shoot for about 25% of the tank volume, or approximately 15 gallons.
the ecosystem hang on back refuges do wonders, and they are very small gallon wise... it is all a matter of what you have to work with. larger fuge will allow more macro algae, which will allow more nutrient export. a smaller one will allow pod growth, but will be more limited in nutrient export... so you have to decide what you want it to do for you i suppose and then go from there.
given space, my next fuge will be 2X the size of my next tank, i love them so much.