What Light is Good for a Refugium? 

Back in the early days of the hobby, there were not many choices when it came to lighting. The basic options for light fixtures were fluorescent or metal halide. Since then, there have been major advances in lighting technology. Today we have so many choices it can be overwhelming! Just like with choosing lighting in the display, the same considerations must be made with light in the refugium. In this article we will go over some of the best options for fuge lights and what factors might influence the decision.

Does Macroalgae need a special light?

The answer to this question is – well, it depends. The truth is that any light that can grow coral has the potential to grow macroalgae. However, just because the macroalgae will survive does not mean it will flourish. We need to look at our fuge goals before determining the lighting requirements.

First, we need to think about how densely populated the display tank is. One of the main priorities of the fuge is to naturally filter wastes. If we have a display that is housing a dense fish population, we will set our sights on a fast-growing macro. AlgaeBarn would suggest using two varieties of macro for this type of system. Chaeto and Sea Lettuce are a great team for soaking up excess nutrients from the water column. They grow very fast with the right conditions. Chaeto and Sea Lettuce grow best under full-spectrum and bright lighting. For a fuge system like this, we would recommend the IM ChaetoMax or the Kessil A360X.

Do I Need to Use LED Lights in a Refugium?

LEDs have certainly become the preferred choice over metal halide or fluorescent. Metal halide are clearly not the most energy efficient way to light an aquarium. Yet, metal halide lighting offers benefits such as greater penetration depth. However, metal halides produce a lot of heat. For reef keepers that go with this option, additional cooling equipment may be required to maintain temperatures. Chillers can be an expensive investment for the reef tank system. But a chiller might be a necessity if metal halides are used to light a refugium.

Fluorescent lighting has also seen its share of improvements. The days of the old school VHO and compact fluorescent bulbs are long gone. There is a new school of fluorescent lighting, and they are strong contenders. T5 is the most used fluorescent bulb for reef tank systems. T5 bulbs produce a great quality of light. Also, T5 light is very pleasing to the eye! T5 bulbs can grow beautiful and healthy macroalgae as well. The only downside with using T5 is that the bulbs can begin to degrade very quickly. It is suggested that T5 bulbs get replaced every six months to maintain strong growth rates.

Some reef keepers will choose to use a combination of T5 and LED lighting for the refugium. It is also possible to supplement T5 bulbs with an LED strip. This means that if reef keeper can decide to supplement the fixture rather than buy an entirely new fixture. For many hobbyists, this is the most cost-effective solution.

Do I need to have the light on all day?

There is no easy way to answer this question! Like many topics in this hobby, there is no one-size-fits-all recipe for the perfect tank. And the photoperiod is one topic where there is a lot of experimentation. Many reef keepers have reported good results using a nine-to-twelve-hour photoperiod. This would mean that the lights are on between 9 and 12 consecutive hours. Most macroalgae species are happy with at least ten hours of light.

One of the benefits of having a fuge is the ability to keep the pH levels more stable in a display tank. During daylight hours, the macroalgae draws carbon dioxide from the water column. This results in rising pH levels. But this only happens during photosynthesis. And photosynthesis only happens during daylight. At night, the pH levels drop due to the lack of photosynthetic activity.

We can use this to our advantage by offsetting the light cycle to stabilize pH levels. In this method, the reef keeper is operating the daylight hours of the fuge on an opposing schedule from the display tank. When the display lighting goes out for the period of darkness, the pH will begin to drop. Sometimes the pH drops very sharply in a reef tank system. However, if the fuge light is on, the macro is hard at work pulling carbon dioxide from the water. This helps to avoid potential sharp drops in pH.

Do I need a special control for the refugium light?

            The short answer is no, a controller is not needed for a refugium. However, a programmable, automatic timer is crucial. One of the keys to getting strong growth rates in macroalgae is lighting consistency. This just means the light needs to be turning on and off at regular times daily. Also, should any tunings need to be made on the intensity or color spectrum, they need to be adjusted very slowly.

One of the lights AlgaeBarn recommends is the AI Fuge 16HD. Aside from reliability and performance, this LED fixture is compact but powerful. This is a high-intensity light that emphasizes the red color spectrum. Red color spectrum is vital to encouraging strong growth rates in macroalgae. Another reason why we like this light is the capability to adjust color spectrum and internal timer from the myAI App. There is no need for another controller with the AI Fuge HD16!

Conclusion

At this point, we have gone over some of the biggest sticking points that make choosing a fuge light seem overwhelming. Spectrum, intensity, and photoperiod are crucial factors that will influence the functioning of the fuge. When the reef keeper knows what type of performance is needed from the refugium, picking the right lighting is quite simple.

In our experience, light shopping should not be mind-numbing. It doesn’t have to break the bank, either! AlgaeBarn has a great library of resources, and our support team is waiting to help.