An Introduction To Reef Jars
When I first became interested in saltwater aquariums, I was always attracted to the smaller systems. I have been fascinated with miniature ecosystems as long as I can remember, so much so that I started PJ Reefs, a company dedicated to reef jars and vases! At first many people said that it would be difficult to maintain a small "pico aquarium", especially if it was the size of a jar. Also there were concerns that the size would limit the amount of possible combinations, and could not possibly be entertaining to create. Four years ago I started my first reef jar right here at Nano-Reef.com. I shared my journey, a simple jar that would follow me for four years. The following is a write-up on how to create your own container reef (e.g. jar, bowl, vase).
"Simplicity is Key"
Many steps are similar to starting a nano or pico aquarium. One main difference to note, is the simplicity on which these systems are based.
Choosing Your Container
The most important component to build a container reef is the container itself! The shapes and sizes of containers are virtually endless: jars, bowls, vases, candle holders, terrariums, etc. You can find a huge selection of suitable containers at all sorts of local shops, craft and hobby stores like Michaels or Joann, the home goods area of your nearest Target or Walmart, or check your local thrift stores for some truly unique finds! If you can't find something around the house or around town, there's always Amazon.
I prefer curved shapes, as this will create a magnifying distortion which attracts the eye to key focal points in the container reef. For less distortion one can choose a vase that has fewer curves. Something unique about jars are their lids; lids that don’t have rubber gaskets will allow for gas exchange, as gases easily diffuse across small gaps. It is highly suggested to have a lid, as this will help limit the amount of evaporated water from the container.
Glass containers are best suited for keeping a reef because of their durability and overall scratch resistance. Always consider the long term durability of your selected container, anything too fragile could lead to difficult maintenance or disaster.
Selecting Your Light
The light source you choose is important as this is the main source of nutrients and energy for the corals. Small reef spectrum LED lights and compact fluorescent bulbs are ideal choices because they emit the least amount of heat. Options include PAR30 or PAR38 LED bulbs that can be purchased at Bulk Reef Supply and Coral Compulsion, or the JBJ Picotope 9W Powercompact fluorescent light that can be purchased at Marine Depot. I started my original reef jar with a JBJ Picotope light in fact!
PAR LED bulbs utilize a common household E27 lamp socket, allowing for the use of common household fixtures like desk lamps to hold the light over your pico container. Similar screw type compact fluorescent bulbs can also be found in reef aquarium 50/50 spectrums from Coralife.
Getting the Right Flow
Traditional tanks use large return pumps and powerheads to create the water circulation that allows corals to receive the necessary nutrients. For larger pico containers, a mini powerhead pump can provide necessary water movement, as long as space is available. In the limited space of a pico reef jar however, one usually needs to minimize the footprint of a powerhead. To overcome the space limitations, an air pump with an air stone placed at the bottom of the jar or vase is recommended to create the necessary flow. Typically smaller air bubbles are preferred as this will create the smooth flow necessary for the corals to thrive. Large bubbles typically create a non-laminar flow that is not adequate for the corals to thrive.
Put a Lid On It
To minimize water evaporation, it is recommended to have a lid or cover for your container reef. If your container doesn't have a matching clear lid already, a basic cover can be crafted from clear acrylic. When covering your pico container, ensure that the seal is not air tight, it is vital to allow for some gas exchange with the surface of the water.
If a lid or cover is not used, an auto-top off system should be used to replace evaporated freshwater and keep the salinity stable. Monitor your container closely as evaporation rates can change with the seasons.
Preparing the Live Rock and Sand
Due to the small size of the aquarium, aquascaping will typically depend on the shape and characteristics of just one or two pieces of live rock. You want to choose a live rock that is nice and porous as well. Also remember that corals and inhabitants will need space to grow, leave extra room for them to fill in the space over time, and don't be tempted to add too much rock.
Sand sand can be added at the bottom of the jar to give it a more natural look if you would like, or your container can be left without sand to allow for easier cleaning. Don't make your sand bed too deep though or it may become too difficult to remove detritus.
How About the Nitrogen Cycle?
Reef jars go through the nitrogen cycle just like any other reef, but due to the small amount of water volume and complete 100% water changes, you might not detect any changes in nitrogen. This is known as a soft cycle. The best practice is to add live rock and let the rock cycle for a few days, up to two weeks, depending on the handling of the live rock. To make certain the cycle has completed the aquarium water can be tested using a test kit for ammonia, nitrite, and nitrate.
Choosing Appropriate Livestock
Just as with a large reef aquarium, livestock should be carefully researched before being added to confined the ecosystem. All life should added one piece at a time, making sure that stability is maintained. Some livestock are better suited for small pico reef jars than others. Here is a short list of some suggested livestock:
Zoanthids are extremely hardy corals that will tolerate a wide range of parameters. Also, some zoanthid species in nature tolerate low and hide tides which exposes them to air and wind for an extended period of time. They are also appealing due to the wide variety of colors available.
This genus typically is larger than their zoanthus counterpart, but they are similar in that they are extremely hardy and also come in a wide array of colors. Because of their larger nature and polyp expansion, you can add a few at a time and allow them to grow and establish a spot in the reef vase.
Mushrooms are flat discs that range from tiny to very large. Because of their flat nature and ability to contort to fill the smallest places, you can place these corals easily on the live rock and they will typically move to find the correct place for them to thrive. They come in a variety of colors and shapes, and are very hardy soft corals.
Green Star Polyps
Green star polyps are hardy and typically have a fast growth rate. Because of their fluorescent green colored polyps and resemblance to grass, these corals add movement and color to a reef container. They are soft corals that are very hardy and are easy to maintain.
Acan corals are easily propagated and be fragged into single polyps that will grow into colonies over time. They are a favorite in reef vases because they can easily be spot fed and no excess food will remain in the water column. Care must be taken with placement of these corals though, because they have sweeper tentacles that can sting nearby corals. It is best to leave a bit of space between acans and other nearby corals.
Almost any coral that is of an appropriate size can be maintained in the reef vase aquaria. The needs of each type of coral, including lighting and flow, must be taken into consideration. It is important to note that the same principles and concepts apply from larger tanks. Water parameters and maintenance are still important to allow your reef to thrive and flourish.
Macroalgaes can also be added to reef jars. They come in a variety of colors and textures and have the added benefit of assisting with nutrient export. Typically, species of red pigmentation are desirable as they are hardy and add a nice pop of color to the reef. Gracillaria and red grape are common varieties of red macroalgae that do well in these aquariums.
Suitable Fish and Invertebrates
Depending on the size of the aquarium, fish species that are suitable for container reefs are few and hard to come by. For larger containers, certain small gobies can be kept if their feeding needs can be met. However, most container reefs do no contain any fish, and instead focus only on corals and small invertebrates. Mainly shrimp, snails, and small crabs can be maintained in container reefs. Some of the invertebrates commonly kept in container reefs are sexy shrimp, pom pom crabs, anemone shrimp, small hermit crabs, and small snails. Research is key, as some species have very specific needs that must be met to successfully keep them, never assume!
Maintaining Your Reef Container
Keep your newly created ecosystem under your light source (you can use a digital outlet timer to control your lighting cycle) and you are ready to enjoy your reef. With the proper maintenance you will be on your way to seeing your reef grow and thrive!
There are five simple maintenance requirements to keep a successful reef jar:
- Complete a weekly 100% water change. This will replenish any lost ions and reset the water parameters. One of the benefits of owning a reef jar is that it is easy and affordable to do a complete water change.
- Maintain the temperature between 76° and 82° Fahrenheit. The most important part is to keep a stable temperature with no drastic fluctuations (e.g. 4-5 degrees within an hour). Add a low wattage aquarium heater to your container if needed.
- Top-off with of RO/DI freshwater as water evaporates from the reef container. Adding a lid to your container will help to minimize evaporation, just make sure it's not an air tight seal!
- Maintain sufficient water movement and circulation. Add an air pump and air stone to aid in water movement and gas exchange. Alternatively, small powerheads can also be used for water movement.
- Do not overstock corals and animals. Have patience as drastic additions can quickly have a negative outcome.
Enjoy Your Pico Reef
Now you know the fundamentals of how to build and maintain your own small container reef. It is simple and fun to do! When properly maintained your container reef can be enjoyed for years to come. I have successfully maintained a reef jar for four years, others have had theirs for over 10 years now!