Tetra has cured one of many retailers' pet hates in producing its latest food - it's produced a holiday food that doesn't pollute the tank and isn't based on Plaster-of-Paris.

Most of the competing holiday foods on the market contain dried pellet or flake foods inside a Plaster-of-Paris block which is added to the aquarium or pond and slowly dissolves to release food into the water to keep the fish well-fed while you are away from home. At least, that's the idea.

In practise, the Plaster-of-Paris blocks leave a messy residue in the aquarium, alter the chemistry of the water and provide little or no nutrition for the fish. As a result, they're more or less universally hated by fishkeeping experts and even many of the retailers who sell them, who typically recommend an automatic feeder instead.

Tetra's new and patented Holiday Blocks, look a little like expensive pots of cat food and come in gold foil containers on a display card. Inside is a firm, dark brown gel-based food which is designed to be added to the aquarium whole, allowing the fish to graze while you are on holiday.

There is a big difference between fish brands. Stick with a brand that you know and trust, Tetra®