If you are a fish-geek like me, you have likely accumulated a basement, attic, crawlspace, or garage full of used equipment. This same graveyard of aquatic supplies is sure to bring you scowls of disapproval from your family, spouse, or significant other. It will also fuel disagreements when you feel your current inhabitants could benefit from the newest piece of technology to hit the market. "What do you need that for? Why can't you use something from that pile cluttering up the garage instead? If you are not going to ever use any of that stuff, what are we storing it for?" To save yourself that kind of grief, put as much of it to good use as possible or get rid of it.
It was with this mentality that started me clearing out the garage. I was selling most of my "prized" stuff for ten cents on the dollar just to get rid of it. School had just begun. Winter would arrive in Pittsburgh before I knew it and if my wife could not park her car in the garage because of my fish stuff, I would have a long, cold season in store for me.
During this cleaning, I stumbled across an old Hagen Aquaclear 500 and a brand new Coralife Mini-Might. I had gotten the power filter years ago as part of a complete freshwater tank setup. I bought the whole thing at a garage sale, but I just wanted the tank and stand at the time. It has since sat in the garage collecting dust. The light fixture I bought new during a clearance sale at a local fish store. I had no reason to buy it other than it was only twenty bucks. A brand new, nine watt, power compact light fixture with the lamp included, how could I pass that up? So, that too went into the garage.
Recently, I decided to combine these components into a hang-on refugium. If you don't know what a refugium is, briefly it is a place of refuge from predation by fishes. They usually hold some sort of macroalgae for nutrient export, hopefully a myriad of small creatures for plankton production, and perhaps a deep sand bed for denitrification. There is in-depth coverage of design options and inhabitants in Anthony Calfo and Robert Fenner's Volume One of the Natural Marine Aquarium Series "Reef Invertebrates" if you are interested. A detailed discussion of refugia is simply beyond the scope of this article and likely unnecessary for the majority of the readers.
Converting this power filter was rather simple. The only tools you need are a Dremel and Superglue. What kind of reefer doesn't have these lying around? First, remove the filter basket. Then, cut the lid so that your light has unobstructed penetration into the old media area. In this instance, I cut a 4" by 9" rectangle out of the filter cover so that this hole was centered over the now new refugium space. Next, take some of the lid material to create a barrier to keep the substrate away from the pump assembly. I started with a 4" by 4" square, but you will notice that the Aquaclear filter has a slight taper to it. This can easily be trimmed to fit snuggly and secured into place with the Superglue. It took me some time shaving the square to fit right, but once you have done that, you can quit. I ended up going a little further with mine. I took some more of the leftover lid material and made little tabs to help keep the light fixture in place. Again, I simply fastened these into position with the Superglue.
With this small of a refugium, you really need to narrow your desired applications. For instance, some refugiums can be designed to maximize denitrification by utilizing a remote deep sand bed (DSB) for those that want the benefits of a DSB but don't want to put one in their display for fear of some future possible tank crash. Others may have nutrient export through the use of macroalgae as there main purpose. Still other's primary function can be for plankton production. There are even some individuals who would sacrifice some of these tangible benefits for aesthetic purposes. They may grow mangroves, for example, not really for nutrient export but because they are interesting, unusual, and attractive. And lastly, there are those that wish to combine all of these aspects into one compromise refugium.
In this size refugium, because of the shallow depth of substrate and small amount of surface area, a significant amount of denitrification is unlikely. For some of the same reasons, plankton production is going to be minimal. The main reason I wanted this refugium is for growing macroalgae in a confined area and its subsequent nutrient export.
I chose not to get too detailed with the dimensions for cutting the hood because I don't assume everyone will be attempting this project using the same parts. I used the Mini Might because that is what I had lying around. If you don't have one of these light fixtures, I am sure a suitable substitute could be fashioned from ahsupply.com parts or some similar vendor. I just wanted to demonstrate how simple a project like this can be and encourage others to try to be creative and come up with some interesting and useful DIY ideas.
I really like the large Hagen Aquaclear power filters for this. They hold a large water volume and give you the ability to control the flow rate of the water. If you don't have one of these just about any hang-on power filter would work. Another example would be an old E. G. Danner/Supreme Aqua King or Super King power filter. The only downside is the Supreme filter uses a siphon to draw tank water into the filter and a pump to return it. The Hagen units, on the other hand, use the pump to suck water into the filter box and then allow the water to gravity feed back into the aquarium. The Hagen arrangement is better because it poses no risk to planktonic life forms from the impellor. The large power filters from Marineland (Penguin and Emperor models) and Tetra (Whisper units) can be used, but because they mount the pump in the middle with the filter media areas to each side, lighting can be a little complicated. You don't want to illuminate the impellor assembly and encourage algae growth there since it would be difficult to clean without taking the entire thing apart and seriously disturbing the refugium substrate.
I would recommend one of these Aquaclear refugiums for tanks easily up to 30 gallons, perhaps as large as 55. After that, the small size is going to be a limiting factor, making its addition have little to no impact. But, on a ten or even twenty gallon aquarium the Aquaclear's size and 500 gph linear flow rate could be a significant benefit to circulation, surface agitation, oxygenation, and nutrient export.
I chose to use the refugium I built on a 10 gallon tank I also uncovered in my garage. I set up this aquarium at my wife's school where she teaches Sixth grade science classes. It worked well as a teaching aid during the time they were discussing ecology and the environment. Plus, the tank has to come back home during the summer break, so I should be able to sneak it in as a nice mini-reef tank addition without any complaints from my better half. Good luck with your DIY projects!
Re: DIY AquaClear 500/110 Refugium'¦Lighting --
R2: DIY AquaClear 500/110 Refugium'¦Lighting --
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Hagen DIY Refugium Article Offer 11/22/05 This article I wrote appeared in FAMA a few months ago. I thought you might like it for WWM. I also have some images for it. -Steven Pro <Thank you for this Steven. Will post, along with your pix/graphics if you'll send them along. Might I ask, are you attending Interzoo this coming year? Interested in the Red Sea afterward? BobF>
Hagen DIY Refugium Article Offer - II 11/22/05 No, I don't think I will make Interzoo this year. I am speaking at the Midwest Marine Conference, IMAC, and SaltwaterU2 all around that time. <Man! It's your new job! I do hope we can get out dive/traveling some time soon> Here is the first picture. I will send more along separately. <Thank you. BobF>