Everyone loves the cute, and low maintenance style of the traditional bowl aquarium. Unfortunately, your typical fish- bowl-with-goldfish scenario is not only tacky and outdated, but often a poor environment for any fish. My personal philosophy is that you can create an aquatic ecosystem on a small scale, and have stylish results, when it’s created with care and appreciation for its inhabitants.
Choosing your ‘bowl’ is one of the most fun parts of making a nano tank. I like to go to my local thrift store and see what they have to get something more original. Pick something out with a wide open mouth, and not too much thick convex glass, as it will distort the look of your fish. Votive-style vases are some of my favorite, but I have seen other things like juice jugs, jars and pitchers with taps make really cool tanks as well. You want to aim for a size of 1.75gal – 6gal. Anything smaller will just be too small to maintain the beneficial bacteria you will need for your ecosystem.
I always do layered substrate. On the bottom layer, you can add some carbon or ammonia Zorb for extra biological filtration. The biggest problem with nano tanks is they lack a filter to store bacteria. You want to have as much porous surface as possible. This way, bacteria can collect and convert all the waste that will build up as harmful nitrates and ammonia. You can top your biological substrate off with some aquatic soil, and even top that layer of with some larger decorative stones. Finer gemstones like amethyst, agate, fluorite or jasper, can make a really nice addition to a vase-style tank. I have a selection of fine quality stones in my shop.
Air and Heat:
Nano tanks can be successful without a flowing filtration system, but any tropical fish species is going to want some air and some heat. Check out some air stones and the ‘quiet’ model air pump to give your fish some bubbles. To achieve the low-tech vibe, you want your air pump to be super quiet. Attach some simple long length tubing and you can even run your setup farther away, for the discrete look. Mini-heaters are also available which can work for 2gal and up, as you don’t want to overheat the small space.
Plants and decor:
This is the fun part! Building a scape involves a lot patience but can be really rewarding. Forceps, scissors and other aquascaping tools are essential for strange shaped containers. Most aquatic plants will do fine in a small container without C02. Floating plants are also recommended as they create a ceiling that can prevent your fish from jumping out and dust from falling in. Bamboo can also really purify the water. All the plants will help pick up nutrients from the water and create oxygen. Personally, I like to dress nano tanks up with some crystal and driftwood elements. I hate anything plastic and feel that quartz clusters can give it a more ‘expensive’ look while keeping with the natural peaceful aquarium feels.
Personally, I would not deviate much from this list. Not every species works as a nano species. They need to be hardy, as the water will fluctuate a lot with each cleaning. But, they also need to be well-suited to a small space.
Small species 1.75gal- 4 gal
White cloud minnows- bonus no need for heat
Otto catfish – bonus algae eater
Larger species 4-6gal
Fancy guppy varieties
Galaxy tetra/ celestial danio
Zebra /leopard Danio
Snails are a must for any aquarium. My favorite are nerite snails as they don’t reproduce in freshwater. But, if you like snail babies, then Ramshorn snails make a great addition to any tank, and you can give the extras to your friends. They are great algae munchers.
Any of the small species listed can also be paired with shrimp. My favorites are cherry neocaridina shrimp as they can handle some fluctuation in water parameters. I have also kept amamo shrimp in un-heated 4gal with great success. Shrimp are great in nano tanks but they should be added after they tank has matured a couple months as they can be sensitive when they molt. Shrimp also will clean up the waste from the snails and sort of completes the eco system circuit. It can be tricky to maintain a small system with just shrimp, so having them paired with small fish and lots of snails makes for a fun habitat.
This is just a basic outline, but I hope its helpful in brainstorming ideas for your nano tank! What’s important to always keep in mind with nano tanks is that this is miniature habitat that needs to be developed with natural elements, and needs to mature for a few weeks before you add any fish. Its always important to monitor your tank, no matter how small, so you can keep tabs on your fish’s health!