The Artful Ecosystem
An expertly planted nano tank is a true work of art.
Gazing at these mini fish tanks transports you into a miniature world where tiny fish and shrimp scurry about looking for algae and other bits of food.
There’s something about a micro-scale aquascape that captivates the imagination; the mind delights at how a small-scale habitat can mimic a larger ecosystem.
What is a Nano Tank?
The term “Nano Tank” refers to small compact tanks (often cubes) designed for desks or small spaces.
The aquarium industry and hobbyists have not reached an agreement over what qualifies as a nano tank, but, for me, nano tanks are aquariums of less than 10 gallons.
In my eyes, a 10 gallon is a standard aquarium that simply provides too much room to qualify as a nano tank.
A huge selection of fish can be kept in a 10 gallon tank and finding a filter, heater, and light for a ten gallon is fairly easy.
But, when I think nano, I think of challenging choices about tank design.
From heater and filter, to substrate, hardscape, plants, and fish—all require forethought and artfulness to bring the tank into a cohesive whole.
Everything needs to harmonize.
Nano tank have become a favorite of aquascapers for this reason, providing an aquatic canvas for those crafting real and imagined landscapes in these tiny ecosystems.
Nano Tank Aquascaping
Aquascaping a nano tank challenges the aquarist to arrange a number of variables into a visually pleasing and cohesive whole.
A common mistake made by many beginner aquarists skimping on gravel and substrate.
These aquarists will buy basic gravel, add plants, and maybe some root tabs or liquid fertilizer and end up wondering why only algae seems to flourish.
If you want a lush planted nano tank, high quality substrate is required.
Substrates like Seachem fluorite, Eco-complete, and Fluval Stratum possess key nutrients and micronutrients, which are slowly released and broken down by aquarium plants.
For a review of the best planted tank substrates, check out my article here.
A quick dose of liquid fertilizer may help your plants temporarily, but that fertilizer will quickly dissipate and your plants will go hungry.
Substrate is the backbone of a planted aquarium, so invest some money in the good stuff.
The hardscape of your nano tank—rocks and drift wood—is the skeleton of your aquascape.
If these elements are not arranged in a pleasing setup, the tank will look blah rather than stunning.
Popular stones for nano tank aquascaping include:
1) Dragon stone
2) Seiryu stone
3) River stones
Popular wood for nano tank aquascaping include:
1) Manzanita wood
2) Malaysian driftwood
3) Mopani wood
Each type of hardscape material has a distinct aesthetic quality, and combining those qualities into a beautiful whole is the genius of a skilled aquascaper.
Texture, color, distance apart—these are just beginning considerations when crafting an aquascape.
Choosing slower growing plants for a nano tank setup prevents the tank from turning into a weed bed.
Anubias, Java fern, and Java moss are excellent additions to a nano tank because these plants tolerate low light and are slow growers.
For a review of other hard to kill, low light plants, check out my article here.
Aquarium plants like Monte Carlo (Micranthemum tweediei) and dwarf hair grass (Eleocharis acicularis) are also beautiful additions to the foreground and midground of a tank, but these plants require stronger lights and benefit from CO2.
Setuping up a CO2 system or investing in high-powered lights can be daunting.
Beginning your aquascape with forgiving low light plants (like Anubias) will give you time to adjust your setup for more demanding aquarium plants.
A low to medium light nano tank setup is very achievable and looks amazing.
Choosing the right fish for a nano tank is where many aquarists go wrong.
The small size of the tank is not ideal for most commonly kept aquarium fish.
Even small fish like neon tetras are not perfect fish for a nano tank because these fish like to school, and a fully scaped nano tank has limited room for fish to swim back and forth.
What Are Ideal Nano Tank Fish?
Some of the most ideal inhabitants for a planted nano tank are not a fish at all, but rather shrimp.
The minimal bioload of freshwater aquarium shrimp, such as cherry shrimp, will not overpower your tank’s waste management system the way fish do.
And, aquarium shrimp are available in a range of colors, including red, yellow, orange and even blue.
Learn more about beginner aquarium shrimp here.
If shrimp are not for you, don’t worry, a small but striking number of miniature fish make great additions to a nano tank.
Some of my favorite nano fish include:
Endler’s livebearer or Endler guppies, are small, hardy fish originally discovered in Venezuela.
Males display striking colors, including neon orange, blue, yellow, and green.
The average size of a male Endler’s liverbearer is between ¾ of an inch to 1 inch.
Females tend to be a little larger, often between 1.5 inches to 2 inches.
Endler’s livebearers make great additions to a planted nano tank because they are able to tolerate a wider range of water conditions than other nano fish and their small size will not burden your tank’s waste management system.
Pygmy corys, reaching a maximum length of about 1.2 inches, are some of the only corys that can be kept in a nano tank.
In fact, in tanks with larger fish, these tiny corys may be harassed or even eaten.
Pygmy corys feel most comfortable in schools of 6 or more, so a tank of 5 gallons or larger may be necessary.
Corydoras are a bottom dwelling catfish species, and make an excellent cleanup crew for your tank, eating fish food and bloodworms that fall to the bottom of the aquarium.
Note: providing a smooth surfaced substrate, like Fluval stratum, is important because corys can injure their whisker-like barbels on sharp surfaces like lava rock.
Betta fish are not exactly miniature fish, but they do well alone, unlike tetras, which thrive best in schools of six or more fish.
While many people keep betta fish in containers of 1 gallon or less, such conditions often lead to early betta fish deaths.
Ideally, a betta fish will have at least 2.5 gallons of swimming space.
So, if you are setting up a planted nano tank, a tank of 5 gallons or larger will provide enough space for aquascaping as well as room for your betta fish to swim around.
If you want to learn more about betta fish care, check out my article on how to properly keep a betta fish in a bowl.
Or, if you want to keep fish other than a betta fish in a 5 gallon aquarium, check out my article on some of the best fish for a 5 gallon tank.
Nano Tank Filters
In addition to making a nano scape beautiful, and aquarist must also make it functional.
Aquarium filters are vital to the health of a nano tank because water conditions are fluctuate more readily in smaller tanks.
Aquarium filters help maintain a healthy nitrogen cycle by providing oxygenation and a home for nitrifying bacteria colonies.
Choosing a filter for a nano tank is challenging because most filter are designed for bigger tanks and look out of place or ugly in a nano tank.
Ideally, well placed rocks and plants would hide a nano tank filter from view.
Some nano aquariums come with a built in compartment in which to hide the filter and heater.
Sponge filters make excellent nano tank filters because they are quiet, low flow, and will not suck up tiny creatures like baby shrimp.
But, sponge filters are bulky, and not exactly pretty to look at.
Hiding one in a 3-gallon tank is tricky but can be done.
Nano Tank Heaters
Putting a small heater in a small tank makes sense right?
Yes, but quality matters a lot in a heater and, in my experience, heaters designed for nano tanks tend to be poor quality.
While heaters labeled “betta heaters” in pet stores sound like a good idea, in practice these heaters are inefficient and break after a couple months.
Most small heaters also lack fine-tuning of tank temperature.
Instead of keeping your tank at 78 degrees F, your tank may fluctuate throughout the day potentially stressing out your fish.
Currently, I am trying out a Cobalt Aquatics 25 watt heater for tanks up to 6 gallons. The heater claims to be accurate to plus or minus .5 degrees F and is housed in a shatterproof outer casing.
Nano Tank Lights
Nano tank lighting considerations are generally the same as for any aquarium.
But, planted nano tanks often have an advantage over bigger tanks: they require less light output.
Larger tanks are often deeper, requiring light to travel through many layers of water before reaching plants.
In a nano tank, the distance the light must travel to reach plants is far shorter.
Therefore, less intense lights can be used to grow plants in a nano tank, which translates into a lower electricity bill for you and the lights themselves are less expensive.
I recommend purchasing an LED light for your nano aquarium; these lights are more efficient than comparable T5s and last quite a bit longer.
If you want to learn about PAR value and the lights I use to grow my aquarium plants check out my article on aquarium lighting.
Building your first nano tank aquascape is a blast.
Remember, there is no right or wrong way to design your tank.
Some enjoy replicating a scene in nature, while others take it in a “modern art” direction.
Whatever you do, have fun and let me know how your scape turns out.
For those who love small tanks and ecosystems, check out my article on building a DIY Ecosphere, which is an exciting way to learn about and observe the aquatic creatures that live in local creeks and streams.
Stay zen, aquarists.