Sea lettuce (Ulva lactuca) is an extremely versatile refugium macroalgae. It’s big, verdant fronds can add a little “greenery” to a reefscape. Highly palatable and nutritious, it serves as an excellent live food for larger herbivorous fish and invertebrates. Its broad “leaves” can grow in dense clumps, providing an enormous amount of microhabitat for small, …
Refugium Education
Reef aquaria have gotten a lot more impressive over the years. Much of this owes to a greater awareness of, and emphasis on, the base of the natural marine food chain. This necessarily has also made reef aquaria a bit more complicated. Why? For the same reason we leave out a food dish, instead of a whole, open bag of food, for our dog. Control! At the lower base of the food chain—the very bottom, actually—are the primary producers. This role is played by various autotrophic bacteria, algae and plants. At the upper base of the chain are certain (usually tiny) intermediary organisms ranging from protists to microcrustaceans (e.g. copepods). In this model, the autotrophs “make” their own food energy and biomass from inorganic sources of energy (e.g. light) and inorganic carbon (e.g. carbon dioxide) respectively; the intermediary critters feed on this food source, transferring it up the food chain as they are consumed by predators such as small fish. Small fish get eaten by larger fish, and so on… The most amazing thing about all of this, especially in aquaria, is the efficiency with which nutrients are recycled. Waste products (excess nutrients originally sequestered by the primary producers) that are generated by the “consumers” along the way are all rediverted back into autotrophic pathways. This is where the refugium comes into play. The refugium is an auxiliary tank on your main, display tank. It serves as a sort of refuge for both primary producers and primary consumers (i.e. intermediaries) such as pods. There, desirable and beneficial macroalgae are cultivated out of the reach of large, gluttonous herbivores such as tangs. Pods proliferate there too, safe from the constant predatory pressure of small fishes like damsels, gobies, etc. Even so, as the pods reproduce, they drift out of the refugium into the main tank to continuously feed fishes, corals, and so on. As the macroalgal bed grows to maximal carrying capacity, it is harvested and either discarded or (better yet!) fed out as a nutritious live veggie for fish and invert herbivores in the main tank. In this section you will learn how a refugium planted with macroalgae improves aquarium water quality and compete with bad algae, how refugia support maximal pod populations and how to smartly install/operate refugia in your own aquarium system.
5 Fish for the Refugium
For a lot of people, a refugium is an opportunity to keep an “extra” tank. This doesn’t necessarily mean more of the same; in fact, the refugium typically houses stuff that you cannot keep in the “main” tank, like Refugium Fish. Generally, this consists of macroalgae. The idea is that in the refugium, macros (1) …
Advanced Refugium Lighting
Planted refugia are used to cultivate macroalgae. And that’s about the only thing that has stayed the same over the years. As time goes on and the saltwater aquarium hobby becomes more and more sophisticated, these set-ups are becoming increasingly complicated, specialized, and technologically advanced. They are designated for many different types of uses (nutrient …
Blue Hypnea: The Next Hot Refugium Macro?
Though it sells out quickly when available, blue hypnea is out there for the grabs. And it’s well worth it for those that cater to its needs! This gorgeous plant can really spice up a refugium; it can also be displayed in the main tank (assuming no large herbivores are present) because it cannot overgrow …
Building Your Mangrove Biotope
Ahhh, the planted refugium… It’s become something much bigger and much more engaging than the mere “filter” it was just a few years ago. Where we once were happy just to keep a big wad of chaeto or some such seaweed in an otherwise empty tank, we moved on to try a broad variety of …
4 Macroalgae for Beginners
Macroalgae are a great addition to any aquarium. They remove excess nutrients in the water column (such as phosphates and nitrates) and provide shelter for copepods which helps with successfully breeding them in your tank. There are many different types of macroalgae; in this article I will be discussing the best types for beginners. Macroalga …
Link’s Gobies in the Refugium
With perhaps 20,000 fish species inhabiting our planet, it’s hard to imagine that we’ve already fully explored the potential for each of them as aquarium subjects. Truth be told, there are probably thousands of species that have yet to be discovered in the wild. For sure, a good place to start looking for cool “new” …
Pom Pom Macro as a Replacement for Chaeto?
It appears that the chaeto macroalgae (Chaetomorpha spp.) has become what Caulerpa was around the turn of the millennium: The predominate go-to refugium macro. And it really can be great for this purpose. That being said, it has (like Caulerpa) its own set of advantages and disadvantages. In reviewing both the pros and cons of …
Types of Aquarium Lighting
Aquarium lighting has come a long way. There are now many, many different types to choose from. For sure, different lighting systems have different capabilities. The one that is best for you all depends on what you plan on keeping in your tank. If you don’t plan on keeping any photosynthetic organisms (corals, tridacnid clams, …
Mixed Macros in the Planted Refugium
There are plenty of reasons to install a planted refugium into your reef aquarium system. You might culture macroalgae for numerous purposes including removing excess nutrients, growing a live food for herbivores, creating pod microhabitat, or just for simple enjoyment. Some macros are better suited for some of these purposes than for others. Therefore, if …
Getting to the Bottom of Refugium Substrates
These days, it seems as though a pretty solid majority of reef aquarium systems include a refugium. The growing popularity of refugia has been more a glorious resurgence than a successively rising trend. Indeed, they were quite commonly used in the hobby in the early 1990s. Unlike the refugia we’ve been seeing today, however, the …
Red Macroalgae for the Moderately Illuminated Refugium
While there are many species of green, brown and red macroalgae (i.e. multicellular algae) in nature, it is the greens and reds that are most commonly used in planted refugia. Each species is attractive for its own unique set of positive characteristics. Still, one could draw generalizations about each of these latter two big groups: …
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How to Fully Condition Your Dry Reef Rock
We’re all subject to impatience. Particularly when we’re anticipating a highly gratifying event, such as adding the first round of corals to a newly set up reef aquarium. Thankfully, using dry rock, it only takes a few extra days to help ensure a clean and pest-free system from the start. There’s even an added bonus: …
Pod vs Sock: Do Mechanical Filters Kill Copepods?
Considering that aquarium keeping is a mere nerdy pastime, it can be surprising that there are so many contentious issues amongst hobbyists. One such big “controversy” centers around the impact of mechanical filtration (especially filter socks) on zooplankton (especially copepods). Naturally, as one of the world’s largest commercial producers of copepods, we have a couple …
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Using MarinePure in the Aquarium, Sump and Refugium
Managing dissolved nutrients–especially ammonia, nitrite and nitrate–is among the major tasks of reef aquarium husbandry. Accomplishing this can be easy or difficult, cheap or expensive, depending upon how you go about it. And there are lots of ways an aquarist can go about this job. This ranges from operating planted refugia to performing massive regular …
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What are Coralline Algae?
There are all sorts of bad algae–hair, slime, turf–and they are widely recognized by aquarists as a manifest sign of poor water quality. On the other hand, a healthy growth of calcareous algae is regarded as desirable. Calcareous forms are slow-growing yet they compete for space with (and thereby suppress) all the ugly bad forms. …
Eliminating Algae with Siphonaria Limpets
In case you haven’t noticed, marine aquarium hobbyists have really upped their standards lately with respect to algal fouling. These much cleaner, healthier, natural-looking tanks surely are the fruit of numerous advancements in water filtration/treatment techniques. But we’ve slipped a few other cards under our sleeves, too; we’ve added an important new component to the …
Cryptic Zones in the Refugium
What are Cryptic Zones, Anyway? The planted refugium and its associated cryptic zones have gained a lot of traction among reef aquarists in recent years. This has largely been the result of a growing awareness of the need to control excess dissolved nutrients (e.g. nitrate and phosphate). As hobbyists experiment with specifics like macroalgae species …
A Look at the Pom Pom Macroalgae
Of all the genera of macroalgae regularly used in planted refugia, Gracilaria quite arguably has the most representatives. While there are a few very soft and feathery varieties (most of which belong to the “ogos”), there are some Gracilaria spp. that are rather stiff and leafy. Perhaps the most popular of these fat-fronded varieties is …
Building Your Refugium Clean-Up Crew
No one ever said that keeping reef aquaria is totally uncomplicated. Especially keeping them clean! Sure, some maintenance approaches are simpler than others; natural methods are, for example, fairly effortless means to control nuisance algae, detritus and pests. Natural methods certainly require some research, planning and occasional monitoring; but for the most part, they involve …