Depending on where your refugium is located, some of these will work and others won’t. While the most common location for a macroalgae refugium is in a sump, the hobby has been experimenting with other options such as a reactor or HOB.
The lights in this post will be best used in a sump or HOB style refugium. If you are planning on building a DIY macroalgae reactor, then you will need some sort of LED strip lighting that you can wrap around it.
I have owned both the Kessil H80 and the Emmmsun Grow Light. You can spend several hundred dollars on a refugium light, but if we are being honest, you can probably also find success by just using a clip on fixture and light bulb!
It is well known that macroalgae and plants in general responds to certain colors in the light spectrum. That is why there is a huge market for grow lights and why botanists use special lights to increase the rate of growth in their plants.
So all of the options in this post are considered grow lights. I currently use the Emmsun Grow Lights, because they are inexpensive ($30 at time of writing), and have a built in timer. They work just fine.
Whatever you choose, make sure it comes with a mount, and that you can actually mount it properly to suit the location of your refugium!
5. Kessil H380 Halo II LED Refugium Grow Light
This is the most expensive refugium light on this list, especially after buying the Goosneck Mounting Arm and the Spectral Controller. But Kessil makes the highest quality lights available, and you will know you are getting the best (although at a steep price.)
The Kessil H380 Halo Refugium Light has both an extreme purple and extreme magenta spectrum that you can adjust with a knob. You will have to either turn it on/off manually each day, or buy an inexpensive digital timer to do that work for you. Or, you may just want to leave it on 24-hours a day.
You do not need to purchase the mounting arm, as it comes with metal hooks and hanging brackets, but I believe you will have to gerry-rig something to be able to hang it.
This is a strong light, so if you have a small tank with a small refugium, this is probably overkill.
4. Tunze Eco Chic Refugium LED

This is a really cool light! It’s 100% waterproof, so you can even mount it under the water if you want!
The Tunze Eco Chic was designed as a grow light for both fresh and saltwater aquariums, and can be mounted either perpendicular to the edge or at a right angle by use of a magnet.
It is 12″ long, so you need to make sure it will fit your refugium. It fits glass/acrylic up to 3/8″ thick, so it will work on most tanks.
This is a much less expensive option than the Kessils, and probably works just as well. I’ve never owned this light, but after reading the reviews I am very interested to get this myself!
If you want to run this on a timer, just purchase an inexpensive digital timer and voila, you are ready to grow macroalgae!
3. Innovative Marine AUQA Gadget Chaetomax 2-in-1 Refugium LED
Coming in two sizes, the IM Marine AUQA light is especially great for AIO tanks with rear filtration or HOB refugiums. It comes with both a simple mounting arm but also with velcro, so you can stick it to the back of your AIO setup.
Full of blue, red, magenta, and violet LED’s, this light, like all the rest, is fine tuned to grow macroalgae.
These are small lights, so don’t be confused by the pictures. The double fixture on the right is less than 6.7″ long by 3.7″ wide. The picture just makes it look bigger.
If you are going to run a HOB refugium, then this is a good light. If you are going to have a refugium in your sump, this light might not be the best option, although it will work fine and is relatively affordable compared to the Kessils.
2. Kessil H80 Controllable LED Refugium Grow Light - Tuna Flora
While this Kessil H80 is not specifically designed for refugiums, it will do the job. It is designed with four unique spectral ranges to support the life cycle of plants, so it is a bit overkill for macroalgae.
You can pair this with the Kessil Spectral Controller, but that seems overkill to me. Just plug it in to a digital timer and that will be just fine.
You can either gerry rig some sort of canopy mount, or purchase the Goosneck to hang it from the side of your tank.
The only reason this is #2 and not #5 is because of the price. It is less than half the cost of the Kessil H380!
1. Emmmsun Grow Light

This is the light I’m currently using and it works just fine. it comes with a 3/6/12 hour built in timer, simple metal mounting clip, and three adjustable heads. It has a 5-star rating on Amazon, and is under $30 (at time of writing).
This light is a grow light, but not designed for aquariums, therefore it is not waterproof. So if you are using it in a moist area or it falls into the water, that may be the end of it.
I really like being able to set a 12 hour timer, because I can have this light on all night and run the reverse of my display lights.
You can dim this light and change the spectrum between red, blue, and white. I just use all lights at 100%, but you do you!
Nothing fancy here, but great bang for your buck!