Choosing a Tank

Glass or Acrylic?

There are pros and cons to both, so it basically comes down to individual preference.  Generally, acrylic tanks are stronger, much less likely to break or leak, are clearer, lighter, and easier to move, and better insulated. The biggest downside to acrylic is that it can be much more easily scratched, so care needs to be taken with cleaning and general maintenance.  Glass is less expensive, and is available in a variety of shapes and sizes, but it doesn’t tend to come in the variety of shapes that acrylic does. Glass doesn’t scratch as easily as acrylic, and although glass tanks can of course be smashed if you drop them, they are long-lasting, provided they are handled with care when moving them.  Glass fish tanks also do not tend to hold their value as well as acrylic ones, but unless you are looking to change them regularly, that is a minor point.

What Shape?

The surface of the water is where the exchange of gases that are essential for life to survive in the tank happens.  It is essential for the well being of your fish that there is enough surface area for sufficient exchange of oxygen coming in and carbon dioxide going out.   More decorative or unusual aquarium shapes have relatively low surface area, though this can be made up for by careful planning of filtration and water movement. Generally speaking though, a long, low tank (landscape format, if it were a picture) is a better habitat for more fish than a tall, narrow (portrait format) one.  It will also be considerably easier to maintain and clean.  Bear in mind also the location for your tank: you need to be able to reach inside to the bottom without too much difficulty, in order not only to clean the gravel, but also to do things like rearrange ornaments and care for plants.

What Size?

Aquarium sizes vary from about 5 litres to 1000 litres or more, though the more standard size would be from about 7 litres for a tiny tank to about 700 or 800 litres for a chunky five foot one.

It’s not necessarily the right choice to buy the smallest aquarium as a beginner, as it is actually much easier to care for a larger set-up than a small one, as water quality is much easier to get right and to maintain the more of it there is.  Small fluctuations in water quality have a more dramatic effect on the life within a tiny environment than they do on a much bigger one.  Plus, once you get some fish, it won’t be long until you want more!  So, the best tip when looking at size is that the biggest you can physically make space for, the smoother your journey through fish keeping will be.

Make sure your tank comes with a ready-made stand that is designed to take its weight, or that the item of furniture you plan to site it on is robust enough for the job.  Remember that even empty, a large glass fish tank is very heavy; with gravel in it, it is even heavier, and then once filled up with water, its weight increases massively.  One litre of water weighs one kilogram, so a filled 80 litre tank (which is not huge) will weigh as much as a fairly large person.

There are many tiny aquarium set-ups available, in a variety of unusual designs.  You can get decorative betta bowls, miniature ‘nano’ aquarium set-ups with built-in clocks and night lights, and so forth. These must be handled with care: you cannot just scale down a regular aquarium set-up as a tiny desktop unit.

Smaller displays are suitable for animals and plants that would be lost in a regular tank. Small invertebrates like shrimp—both freshwater and marine—are great for these little tanks. Water stability is extremely precarious with very small volumes—another reason to use them only for the tiniest of inhabitants. Heating, lighting, and filtration are also very difficult with such a small space to play with, though manufacturers are beginning to produce equipment designed especially with these tiny set-ups in mind.

In Conclusion

Whichever shape or size you choose, there are essential factors to consider: the size and type of fish you wish to keep, what numbers of their own kind they need in order to thrive, and what size they will grow to being the most important.

Do not overcrowd your tank.  Even tiny fish need space to swim about.  Some combinations will also need to be able to claim their own territories, and will only be able to do that with sufficient tank space and decorations, plants and so forth.

Many species need to belong to a shoal of five or six to be happy.  Two albino corydoras will behave manically, chasing each other back and forth across the tank endlessly, which might seem like fun to watch, but they will be calmer and far less stressed (and therefore much healthier and happier) with three or four other ‘friends.’

Stock sensibly for your tank size: A 500 litre tank is too small for even one single two foot monster, but could provide a happy home for a huge community of varied other, more modest fish.  And that cute, comical looking plec may look like it’ll fit perfectly into your 2 foot tank, and it will while it’s still a baby, but it will soon grow to a foot long and not have space to turn round.

Research your fish of choice’s habits: you could keep half a dozen angelfish happily in a three foot community tank, but if two of them pair up and start to breed, the other angels, and other species living happily alongside up to that point, would be in danger of being attacked, and someone would need rehoming.

So, weigh up all the factors, make the choices that suit what you need, and get the perfect aquarium for you and your fish.