Of all the controversies making up "the reef hobby" (how best to deliver calcium, use of UV, organism collection and use… which we’ll all be covering in upcoming exhaustive and exhausting installments), the one category we all can agree on is the use of refugiums. A working definition of such a device is elusive. Is it simply another sump? A separate, yet connected tank for isolating new or endangered livestock? A convenient means of adding Berlin style filtration, live sand, more system volume? Yes, all these and more. The benefits to a captive reef of increasing overall water volume, being able to manipulate/add gear to modify water chemistry and physics without dipping into the main/display unit, having a new arrivals/hospital tank are indisputable. How best to go about the addition of a refugium, like much of reef keeping is definitely not.

You betcha. Ask yourself; would you rather have a smaller hard drive? A thinner wallet? Tinier biceps? Of course not! More gallons yields many dividends; dilution of organic wastes, increased stability of temperature, pH, dissolved oxygen, you name it. A refugium of size may double your carrying capacity/safety margin by increasing it’s volume by a quarter. A good deal? Yes.

How many times have you wished for an acclimation, treatment or "bully-separator" tank? You know the script. It should have similar water quality to the main system, it’s own filtration to keep it stable and optimized. What better way to accomplish all this than a tied-in tank that shares the same water, but can be made independent simply? Yes, it’s a refugium.

How disruptive would it be if something ripped off your roof, stuck their hand in and cleaned your place? Moved stuff around? Added a new appliance? For your reef tank(s)’ organisms similar traumas can be avoided to a large extent by remoting such activity to the attached refugium; keeping your hands out except for the occasional algae wiping, rearrangements. Many European set-ups utilize the refugium other than the display tank for heaters, protein skimmers, touchier corals, live rock and algae.

Light/Dark Advantages: 

A popular current topic is the role of light and dark cycles on the diurnal rhythms of natural and captive aquatic systems. Folks with meters, test-kit madness and keen powers of observation are aware of daily variances in chemical, physical and biological phenomena in their systems. Redox, pH, animal activity are all tied together with time and lighting. Inasmuch as our small seawater volumes fluctuate more than wild reefs, there are definite considerations to off-setting the same with an opposed light regimen on a biological refugium/sump. At it’s crudest, all this involves is an alternating set of timers over the main-display and refugium tanks; when one’s off, the other’s on. Voila! No oxygen minima, low calcium, Redox

How to do it:

Separate filtration, light/dark options, pumps/equilibrium…

Refugium Bibliog../Further Reading

 Adey, Walter H. & Karen Loveland. 1991. Dynamic Aquaria: Building Living Ecosystems. Academic Press.

 Dakin, N. 1992. The Book of the Marine Aquarium. Tetra Press, Morris Plains, NJ.

 Debelius, Helmut & Hans Baensch. 1994. Marine Atlas (v.1). MERGUS, Melle, Germany.

 Delbeek, C.J. & J. Sprung. 1994. The Reef Aquarium. Ricordea Publishing, Coconut Grove, FL.

 Fenner, Robert. 1998. The Conscientious Marine Aquarist. Microcosm, Shelburne, VT.

 Tullock, John H. 1997. Natural Reef Aquariums; Simplified Approaches to Creating Living Saltwater Microcosms. Microcosm, Shelburne,

 Refugium article?
Hi Bob,
<Hello Peter>
Kudos on the site, it has been an incredible resource for this beginner. I did have a quick question, though.
<Okay>
Was your article on refugiums intentionally left incomplete? I am confused about some of the plumbing aspects; in particular, how to make sure I don't overflow the fuge & drain my tank in the event of a power outage.
<Ahh, the short piece posted on WWM is indeed incomplete... in fact, the popularity and utility of refugiums is such that friend and co-author Anthony Calfo and I penned a title (Natural Marine Aquariums, Reef Invertebrates) to present more of a complete set of ideas re these tools... some 80 pages of the four hundred page book are devoted to refugium technology>
I clicked on the link for the refugium article (not FAQ), & munched merrily away at it, as I have been with every other article I've been reading from you folks, but then as I'm anticipating the creamy center, savoring every tidbit of knowledge & experience, it fizzles out into:
"How to do it:
Separate filtration, light/dark options, pumps/equilibrium…"
And then only the references. It looks like someone was putting down a couple reminder notes of what they wanted to write into the article, but never seemed to get back to.
<Oh... let me take a look... yes, you're right that's all there is, and indeed that IS all there is... or was. This short "article" was penned/sold/presented in TFH mag. several years back... and it's about all the space they had interest in using... for others the URL on WWM: http://www.wetwebmedia.com/refugium.htm>
I have ordered the Conscientious Marine Aquarist from MarineDepot.com, & am awaiting delivery. Perhaps it is covered in detail here? I will see.
<Mmm, no. Most of CMA was finished in the mid-90's... see Antoine and I's NMA series... Marine Depot as well as Amazon and others offer this title as well... and if you're interested in refugiums it is (as far as I'm aware) the most complete/definitive work to date on the topic>
Perhaps in the meantime, though, someone could complete the article? In particular, I would like to see some diagrams of valve & plumbing layouts.
<Mmmm, me too! Here's my big offer, response: Please do investigate refugiums to the point of authoring articles on their design, construction, maintenance... including aspects of plumbing, pumping/circulation, algal and other organism selection, and their operation/maintenance... and I'll help you place (sell) them to the print and online zines... really>
Thank you for any additional info that can be added to
this section, & of course, for everything else that
has already surpassed my expectations!
Pete Cushnie
<Do consider my offer. Such popularization of these devices is well-warranted. Bob Fenner, who spent a couple of decades trying to convince people to use skimmers, and doesn't want to, make that, doesn't have that much time/patience for refugiums to catch>

Re: Refugium article?
D'oh! What does it mean when you ask a question & get offered a job?! ;-)
<Hee hee! I've stated before that there are few more gratifying propositions than asking folks (or being asked) to work together>
Well, I see at least that I'll be ordering the other book very soon. As intriguing as the offer is, however, I'm afraid it will be quite some time before I'm up to snuff to write an article authoritatively enough to appear on your site! In the meantime, I think the best way I can contribute to the education of your readers is to pen you the odd note occasionally & let others learn from your responses to my misadventures :-D
<Sounds good>
Thank you for your prompt & completely unexpected reply!
Pete
<Be chatting... and writing. Bob F>