2. Neon Tetra. The Neon Tetra is the UK's (and probably the world's) most popular tropical fish. The tiny fish's bright red and blue colouring and ease of care are a winning combination for beginners.

If you’re looking for a peaceful, hardy, and easy-to-care carnivore fish for your 30-gallon tank, Diamond Goby is a flawless candidate. While they are quite timid, the average lifespan of Diamond Goby ...