There is a nasty rumor out there that small aquariums are more difficult to maintain than large aquariums. Well, I am here to put that myth to rest. All tanks require similar maintenance, regardless of size! Some of my most beautiful aquariums have been 20 liters or smaller. If you want an aquarium, but simply do not have the space, then read on!
The first thing you need to know about small aquariums is that all of the same parameters and laws of chemistry still apply. You will still want a filter. You will still have to stick within standard stocking levels. And you will still have to do water changes.
That said, the first thing you should do is purchase a small sponge filter and an air pump. I bury the sponge filter under the gravel to keep it hidden. I use a gang valve to split the output of the air pump, so that the filter does not create to much water movement.
You should decorate your miniature aquarium with small plastic plants, or some hardy live plants if you are going to have a light source. I like to decorate my small aquariums heavily, so that the fish can easily have a little personal time if they are not feeling like socializing.
For fish you have a few choices. One of these choices is NOT GOLDFISH! They are the worst possible choice for a small tank or for a beginner! Common species you can keep are White Clouds, Neons and other small Tetras, a Betta, Cory Cats, Kuhli Loaches, Fancy Guppies, Platies, and Killifish. Most other species are either too large or too territorial to keep in a small tank. Do NOT fool yourself into believing that if you buy it small, a fish will remain small because its in a small tank! This will only prove frustrating to you and fatal to your fish. Even with the appropriate species, I would avoid trying to mix them in such a small aquarium, as it is difficult to predict how they will react. The Cory Cats are an exception.
You will need to do a weekly water change. This is so easy on a small tank that you can do your partial in less than 1 minute. I keep a 2 liter full of water waiting to go into my miniature aquarium. I then use a very small syphon hose to drain out 1/2 of the water. Then I just pour some water into the tank and I'm ready to go until next week. You will probably never have to scrape algae, as you will most likely not have strong lighting. Window light is all you need on a miniature aquarium.
I should also mention that a miniature aquarium does not have to be freshwater. You can use this same setup but simply add about 2 Kg of live rock and some sand. I had an 8 liter setup with a Tomato Clown for about 2 years before moving the Clown to a bigger tank.
That 8 liter tank was then turned into my best miniature aquarium ever. This tank housed 6 beautiful White Clouds which thrived for 3 years before I took them back to the pet shop when I moved. Good luck with your miniature aquarium. I think you will enjoy it!
Written by Mark Lehr