5.5 gallon Reef Tank

5.5 gallon reef

My 5.5 gallon reef is by far my favorite tank I have. Although it is small, I’ve been able to have the corals really thrive, so much that I actually set up a 10 gallon frag tank. As much as I love this tank, I will be setting up a 20 gallon long reef within the next few months and transferring everything from this tank to that one. I originally set this tank up at my desk at work in July 2013 after I took home my 2.5 dwarf puffer tank. I had been curing the live rock and sand prior to setting up the tank.

Tank Wooden CanopyIt has a custom built wooden canopy top and a built in refugium. The wooden top is divided to allow for an alternating light cycle. An alternating light cycle is sometimes beneficial because it helps maintain the pH because instead of biological processes ramping up during the day and slowing down during the night, you have a constant flow.





RefugiumThe refugium part is divided in two sections, one part where I have the pump and heater, and the other I have chaeto, live rock, sand, and miracle mud. The refugium and the whole tank is teeming with pods and other small creatures.

This tank has no protein skimmer, and even without one the water stays crystal clear and I have no algae problems.




MushroomsThe lighting for this tank is actually the same light I used on my dwarf puffer tank. It’s a Marineland 11 inch LED light. The light is not listed as a reef light; however I’ve been able to successfully keep a variety of soft and LPS hard corals. I did try a low light SPS coral, but I think the light just didn’t have enough power unfortunately. I also added a blue LED light strip just to bring out the colors of the corals in the tank.


Now for the tank inhabitants! One of the inhabitants in this tank may surprise a lot of people; however I assure you everything is quite healthy in this tank.




Gold Ring CowrieInvertebrates

  • 1 Scarlet Red Hermit Crab
  • 1 Trochus Snail
  • 1 Nassarius Snail
  • 1 Gold Ring Cowrie (Was a hitchhiker that lived in my refugium until he escaped. Hasn’t caused any issues so I let him stay)
  • 1 Blood Red Fire Shrimp (Sadly just died December 2015)




Candy Cane CoralCorals

  • Candy Cane Coral
  • Pulsing Xenia Coral
  • Kenya Tree Coral
  • Duncan Coral
  • Mushroom Coral
  • Acan Coral



FishMandarin Dragonet

  • Mandarin Dragonet! (I know, everyone take a collective gasp and let me explain)
  • Firefish






Ok, so mandarins have long been thought of as a very difficult fish to keep, and I would say that is partially true. Mandarins, when healthy, are actually very hardy fish. The biggest threat to a mandarin in a home aquarium is starvation. In the wild their diet is made up of copepods and other tiny crustaceans. Many people think a mandarin will starve to death in a tank that doesn’t have 100+ lbs of live rock. While this may be true if they are only eating pods, I supplement my mandarins diet. Many people also think a mandarin will wipe out a copepod population in a small tank very quickly, but I can tell you first hand that’s not always true. I’ve had Bruce, my mandarin, since August 7, 2013, yes I kept the receipt as proof :), and he is still very health and their are tons of pods still in his tank.

Refugium PodsHe has not eaten every pod in the tank, or even close to it. There are pods all over the refugium, and even on the glass in the main tank. Now for the real shocker, as if keeping a mandarin in a 5.5 gallon tank wasn’t enough, I fed my mandarin adult live brine shrimp almost exclusively for a year! I know you have probably heard that adult brine shrimp has no nutritional value, but the problem is all of those facts are analyzing the content on frozen brine shrimp. Adult live brine shrimp really aren’t that terrible of a thing to feed fish, if you are feeding the brine shrimp properly.


Leopard GeckoWay before I kept fish, I was keeping reptiles and amphibians, which eat live crickets. People who keep those animals are familar with gut loading the crickets, which essentially means feeding the crickets healthy food, making them healthier for the reptiles and amphibians to eat. The same concept can be used on brine shrimp. In the holding container of brine shrimp I fed them spirulina powder. Then about 2 hours or so before I would feed the brine shrimp to Bruce, I would put them in a cup with saltwater and Selcon in it. Selcon is a vitamin supplement many people soak their frozen food in. While soaking frozen food in Selcon is beneficial, much of the Selcon isn’t absorbed by the frozen food and is wasted. With live brine shrimp, they eat the Selcon making them highly nutritional, possibly more nutritional than frozen food.

The next problem people run into when feeding mandarins is they starve because they can’t compete against other fish for food. Mandarins examine their food before eating it, and take a while to do this. While the mandarin is examining a piece of food, the other fish are busy eating everything else before the mandarin has a chance. In my small tank, I originally only kept my mandarin and a fire shrimp, the fire fish wasn’t added until recently. I would turn the pumps off during feeding time, and let the mandarin take his time to eat. He actually got so used to being fed by me, he would take the brine shrimp right out of the eye dropper. This allowed me to sneak other foods into the eye dropper and get him to eat them. This was handy if the fish store didn’t get a shipment of live brine in.

Mandarin Eating PelletsFast forward to today, and now my mandarin is actually eating pellet food. I don’t bother with the live brine anymore, because the pellet food is highly nutritious. Even though I have successfully kept a mandarin in a 5.5 gallon tank, I absolutely am not recommending everyone do this. It took real dedication with feeding him, that most people won’t be able to do. I was lucky to have my tank at work, because if I was out for a day or on vacation, I could have people feed him for me. So I want to make that clear, unless you can guarantee to be dedicated to caring for this fish, I don’t recommend putting one in a nano tank. Also, the built in refugium has definitely help provide a sanctuary for pods to grow and reproduce, and I’m sure this has helped my success with my mandarin.

So you may be wondering why, if I’ve had so much success with this nano reef, why am I going to be setting up a 20 gallon and moving Bruce in there? Well, besides keeping a healthy mandarin, I actually want to try breeding mandarins. I recently found a female mandarin, Sheila, who I am now training to eat pellets. I’m going to try a different method than what is described in that link, and if all goes well will document it on the site.


Full Tank Shot Mandarin with crab Duncan Coral with Mandarin ricordea mushroomDuncan CoralFunny MandarinFire ShrimpFirefish