When looking after freshwater fish, you do have to consider the hardness of the water. Some fish prefer the water to be acidic while others don't. After deciding which fish you would prefer, there are some great products out there which really give you a helping hand in maintaining the level of acidity and kits available which give an accurate reading of pH levels. These products neutralise harmful chlorine and heavy metals and at the same time ensure that the water is revitalised.

A question worrying many fish tank owners is this: how many fish can my aquarium hold? Well, as a rule of thumb, most would use the one fish per gallon of water guide. Of course, this rule is only an estimate as larger fish produce more waste and therefore require more water volume. To avoid unnecessary disasters, being generous with your fish to water ratio means you can't go far wrong.

Fish tanks come in a huge variety of sizes and shapes these days. For people with limited amounts of space, there are hexagonal and octagonal tanks which will fit nicely into corners and make the most of the space available.

Tanks start from as small as the traditional fish bowl and increase in size up to around 2 metres, holding approximately 500 gallons of water. If that's not enough variety for you, you can always have one custom-made to one which holds around 2,000 gallons of water (also useful if you fancy going skinny dipping in your own home).

You can pay as much as you want for a fish tank. Whether that is a small amount or a large amount, the more you pay will obviously increase the size of your tank.

In addition, the thickness and quality of the glass will play a role in the final price, as of course will the shape of the tank. Usually, the more unusual the shape, the higher the price tag. If you opt for a tank which has curved glass, which will look far more luxurious, it will be a lot heavier on your pocket than an ordinary rectangular one.

The golden rule to remember is to plan ahead and decide what kind of fish you want, where you are going to put the tank and how much time you can devote to maintaining the fish and the tank.

If you have a small bedroom, don't buy an 8ft long tank. Owning your own aquarium is a beautiful hobby; not only can you admire your own handy work, but there are so many desirable fish out there. This can enable you to make your tank unique to you.