In a saltwater aquarium system, a refugium is a separate location from the display tank that houses water and a protective environment where macroalgae and copepods can be housed and grown. There are many benefits to having a refugium in your aquarium system including filtration of waste, providing a food source for food and corals, and increasing the overall biodiversity of your aquarium.
With so many benefits to a refugium, do you need a refugium on your saltwater aquarium? You do not need a refugium to achieve a successful reef tank, but with so many benefits including a refugium in your system when possible has many advantages.
Read on for an in-depth look at the numerous advantages and some of the considerations of including a refugium in your reef tank.
Reasons to Have a Refugium on you Saltwater Aquarium System
Using a Refugium to Filter and Export Waste
Filtration and nutrient export are the main benefits of having a refugium. To accomplish this task you need to grow macroalgae in your refugium. The most common macroalgae to grow in refugiums is Chaeto. Chaeto is an algae plant that grows with light and nutrients. Light is provided by using a dedicated refugium light and nutrients are supplied by waste from tank inhabitants and feeding. My favorite light for growing Chaeto is Aquaillumination’s Prime HD Fuge.
Aqua Illumination Prime Fuge Led Light Fixture
Fully Controllable LED Aquarium Light From Aqua Illumination. The Prime Fuge is a horticultural spectrum aquarium light for use growing macro algae. Program the Prime Fuge using the free MyAI iOS and Android app.
A growing ball of Chaeto is the manifestation of nitrates and phosphates being taken out of the water. When Chaeto is trimmed and removed from the refugium it is directly exporting waste from your system. A refugium with macroalgae is an effective natural way to keep your water chemistry at optimal levels.
Keeping Algae in the Fuge and Out of the Display
When you set up a refugium with macroalgae like Chaeto and light it, you are essentially creating the ideal environment for Chaeto to grow in the refugium. With an optimal environment for macroalgae growth in the refugium, you decrease the probability of algae issues in the display tank where you don’t want algae.
Creating a Food Source and Increased Biodiversity in the Refugium
As the name implies, a refugium is a haven for various microfauna to live and reproduce. Refugiums are often seeded with microfaunae like copepods and amphipods. Copepods will live and reproduce in a refugium with some of the population making its way through the sump and back up to the display tank via the return pump. These animals are often a food source for both fish and corals. In addition to a free live food source copepods and other microfauna are effective members of the cleanup crew. Their tiny bodies fit in all the nooks and crannies where they will feed off the waste in the tank.
What Goes First a Refugium or Protein Skimmer?
Using a Refugium to Grow Reefing Currency
If you successfully set up an environment where macroalgae like Chaeto can effectively convert unwanted nutrients it will accomplish this by growing consistently. You may get to a point where your Chaeto fills the entire refugium chamber. When this happens you’ll need to trim back the Chaeto to keep it healthy and functioning optimally. To trim Chaeto you simply cut some of it out and remove it from the refugium.
This excess Chaeto can be simply thrown away. I find that most of my tanks once established with a refugium require Chaeto trimming every two weeks or so. Over the years I’ve found that there is often a market for Chaeto as fellow reefers look to start their refugium or need to replenish their macroalgae. So instead of just tossing out your Chaeto trimmings you can sell it, trade it, donate it, or even take it to your local fish store for in-store credit.
Reasons to Not Have a Refugium on Your Saltwater Aquarium System
Three of the most common reasons to not include a refugium in your system can include increased maintenance, cost, and space constraints.
Increased Maintenance
This is probably one of the biggest constraints in my mind when thinking about adding or including a refugium in your system. Refugiums should have their maintenance schedule and not maintaining your fuge can be detrimental. If you grow macro algae in your fuge it is helping filtration by stripping harmful nitrate from the water. If left unmaintained detritus can settle at the bottom of the fuge, continuously break down into dissolved organic waste, and become a harmful nitrate factory. Regular maintenance will include cleaning out the bottom of the fuge and scraping the glass.
What are the Best Substrates to Use for a Refugium?
Ongoing and Setup Cost of a Refugium
Cost can be a constraint when thinking about setting up refugium.
There are two costs to think about when adding a refugium, start-up costs, and ongoing costs. If you don’t have a sump with a refugium chamber start-up costs can be significant. If you have a sump without a refugium chamber and can’t retrofit you’ll need to swap to a different sump and consider plumbing options. If you don’t have a sump at all you’ll need to consider adding a sump with fuge or consider a separate hang on the back refugium. Once you have refugium capability other start-up costs can include a substrate, seeding with copepods, seeding macroalgae, and adding a lighting source.
CPR Aqua Fuge Medium Refugium w pump
CPR’s AquaFuge 2 hang on back refugiums come in three different sizes to meet the needs of marine aquarists.
Once your refugium is set up the can be some ongoing costs including the electricity going to the fuge light and any other items in the fuge that may need refreshing from time to time like adding more copepods or changing substrate like Miracle Mud.
Ecosystem Aquarium Miracle Mud
Miracle Mud has been carefully formulated to include all the essential trace elements, minerals, and components necessary to maintain a successful aquarium. Miracle Mud will continually replenish your aquarium`s concentration of trace elements and minerals for an ideal environment.
Space Constraints When Adding a Fuge
Depending on your home and your system, adding a refugium can be a challenge when it comes to space. Most refugiums are in the sump or separate via a hang on the back option. For these options, you have to have room behind the tank or on the side of the tank for HOB options and room in the cabinet for a sump if you don’t currently have a sump. Some sumps don’t have refugium chambers and retrofitting can be a challenge.
ReefSumper’s Recommendation
I like having refugiums on my reef tank setups. I find them to be little maintenance and overall help the stability of my tanks. I also grow lots of Chaeto and have found little problem in using it as currency in the hobby where I’m able to easily trade it for frags and other goodies. I also think it is a nice natural way to help control nutrients in the water. One of the most unanticipated benefits of the refugium is the coolness factor. As I’ve shown my tanks to visitors who don’t know the hobby they are amazed when the cabinet door opens up to reveal a separate tank (the sump) and are even more in awe when explained the purpose of the refugium.
Related Questions
What are the basic components of a refugium? The basic components of a refugium are a substrate, macroalgae, a light, and microfauna. Common substrates include live rock, sand, miracle mud, live rock rubble, or a bare bottom. The most common macroalgae are Chaetomorpha aka Chaeto. For lighting, there are many options including compact fluorescent bulbs and led options. Common microfauna includes copepods and amphipods.
What are some of the other uses for a refugium? In addition to its normal function of filtration and microfauna housing, refugiums can be used for other functions too. Refugiums can be used as a time outbox for naughty fish, a second tank to house a delicate fish or other specialty fish, ornamental shrimp can be housed in the refugiums, you can even use the refugium to train peppermint shrimp to eat Aiptasia. Remember to only use the fuge for these purposes when it is right for the specimen placed in the refugium.