What Kind of Light Do I Need for a Refugium?

What Kind of Light Do I Need for a Refugium?

Nowadays, almost all refugia have macroalgae and other types of plants in them. This means that they require a light source of their own. Luckily, there are now aquarium lighting systems that are specially designed to provide the very high intensity needed for this as well as a plant-specific spectrum. Moreover, the very best of these specialized fixtures (for example, the ChaetoMax Refugium Light) are made to fit nicely into the often clamped overhead of a refugium space.


Being as your planted refugium will probably be the single most important component of your aquarium’s life support system, and lighting quality will affect its performance more than anything else, we should elaborate on this a bit.


No refugium macro can do its job, much survive, unless it receives sufficient photons to carry out photosynthesis. The compensation intensity is the minimal amount of light a plant must receive for its gross rate of photosynthesis to equal its gross rate of respiration. In other words, it needs just enough light energy to make just enough sugar to at least maintain its basal metabolism. Growth occurs only after the compensation intensity is exceeded. The uppermost growth limit is reached at the saturation point; this is the intensity at which its photosynthetic machinery is working at maximum capacity.

Let’s just put it plainly here: Natural sunlight is incredibly bright. You’re never going to reach anything near the saturation point using an aquarium light. The bigger worry should always be providing enough light, not just for survival but for good growth. Only continuous growth will result in continuous nitrate and phosphate removal! To achieve this--maximally--you’ll want to be sure that your seaweed bed is illuminated not only at the surface but all the way through to the bottom. This usually requires at least as much intensity as one might use to grow SPS corals!

In addition to high intensity, try to get a light that is designed specifically for plants. These types use only red and blue lights (plants generally don’t use other spectra) as to maximize the efficiency of the fixture. Thus, while they look a bit unnatural to the eye, these lights promote the highest growth rates for your plants.

Finally, one big advantage of using a light fixture customized for refugia is that their housing is typically very compact. They might also have extremely adaptable mounting/positioning options. This means that you’ll be able to fit the light into a small area (e.g. within cabinetry) and spotlight the grow space exactly as you desire!


So, what kind of light do you specifically need? Well, a refugium light, of course. It all depends on your budget and what you want to get out of your macroalgae. It used to be common to use cheap lamps to grow macroalgae. Yes, it may have worked to some extent but not as well as todays refugium lights. 

There are several refugium lights available from several companies with a variety of price ranges. Kessil is the most well known for their refugium lights. This A360X Fuge Light from Kessil is top-of-the-line. It is best for large refugiums that need lots of light, especially at its price. Kessil also offers this mid range budget light (Kessil H160). If you want something even cheaper check out this Kessil light. Of course there's also the ChaetoMax Refugium light from innovative marine, which is one of the cheapest. This light works great on smaller tanks and for those on a tight budget, but it leaves something to be desired. Possibly the best refugium light solution is the Aqua Illumination Fuge 16HD light. This light is best for small to medium sized refugiums. The best thing about this light is its controllability through the AI app. All of these options will work great, but AI Fuge 16HD and the Kessil H160 are the best bang for your buck. They aren't as expensive as the A360X, but they are capable of growing macroalgae excellently. 
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