Brightly coloured friendly and highly active, rasboras are an aquarium favourite. Their peaceful nature makes them a great choice for a community tank and their natural hardiness means that they're ideal starter fish for the beginner aquarist. They adapt well to aquarium conditions and can be delightful to watch.

Rasboras are schooling fish and are happiest in groups of six or more. Averaging about two inches in length, they get on well with other schooling fish of about the same size. For best results, keep them in a densely planted tank with plenty of hiding places. 

They like slightly acidic water, so bogwood is also a good choice, providing cover and lowering the pH of the water at the same time. Make sure there are some floating plants on the surface of the water so that your rasboras feel more secure. They can become distressed if directly exposed to bright light for too long.

If you want to keep something really exciting in your tropical aquarium the chances are that you've thought about piranhas. With a reputation as one of the world's most fearsome fish, the piranha is actually quite shy by nature, but will become more confident if properly cared for. A naturally hardy fish, it makes a good choice for the beginner aquarist - provided, of course, that basic safety precautions are taken.

Piranhas are relatively big fish, growing to as much as twelve inches in length, and they need a fair amount of space to swim around, so make sure your aquarium is large enough for them. When young they prefer to live in shoals, but as they get older they become more solitary and territorial. Older piranhas who have not been raised together should not be kept together. They can be kept with larger fish of other species, but may occasionally bite them. Once they are fully grown they will generally leave much smaller fish alone, especially if they have been trained to accept non-live food.

Because of their aggressive temperament they should not be kept with fish much smaller than themselves, but they can get along well in community tanks with fish like cichlids, oscars and plecos.