How to Make Refugium Filters

A refugium is the perfect secondary filter for a saltwater reef tank such as this one.

There are many benefits in adding a refugium to your salt water reef aquarium, the main one being to act as a refuge for delicate organisms. However, the refugium can also act as a secondary filter, by housing various macro algae, and additional live rock and live sand. As water from the main aquarium slowly circulates through the refugium; the macro algae, live rock, live sand, and some other organisms will begin to break down and help to filter out dangerous toxins, such as nitrate and phosphate. This process results in dramatically reducing the need for regular water changes.

Things You'll Need

• 10 gallon aquarium
• Fluorescent light
• Overflow box
• Small water pump
• Flexible tubing
• Macro algae
• 10 lbs Live rock
• 10 lbs Live sand

Instructions

Refugium Filter

1. Place the 10 gallon aquarium, which you will use as the refugium tank, next to the main aquarium's sump.

2. Hang the overflow box on the back of the main aquarium, and connect it to the refugium using flexible tubing. Use tubing no bigger than 1 inch, so that the flow into the refugium stays at a slow flow.

3. Place a small water pump into the refugium and connect the pump to the main aquarium's sump using fexible tubing. You will need to adjust the water pump, so that it transfers the water into the sump at the same rate that water enters the refugium through the overflow box.

4. Place the live sand, live rock and macro algae into the refugium. The most popular macro algae to use is Chaetomorpha, which can be purchased at your local reef aquarium store.

5. Place a florescent light on top of the refugium, so that the macro algae will grow and thrive. Some people choose to run the refugium light opposite to the main aquarium's light cycle, in order to combat the decrease in oxygen and ph levels that occur in most aquariums at night.

Tips & Warnings

• Make sure you have a slow, steady flow in and out of the refugium. The refugium is most beneficial when the organisms housed inside have time to break down proteins in the water.

• Be aware of leaks and the possibility of overflow. Check thoroughly before allowing the refugium to run unattended.

References

• Fishlore.com: Refugium Setup for Saltwater Aquariums
• Peteducation.com: Refugiums: How They Work, Benefits, and Types
• Reefland: Best Plants and Algae for Refugia By: Anthony Calfo