Want to keep fish but are unsure which tank to go for? Get started the right way with the Swell Buyer’s guide to aquariums.


Tanks range in size from just 20cm in length and 10 litres in volume to 150cm and over 400 litres in volume and larger. All are capable of keeping fish alive but a small tank will restrict the sorts of fish and the number, versus a bigger one. Decide on the sorts of fish you would like to keep. If you would like lots of colour and movement then a community aquarium with lots of different types of tropical fish all living in harmony is the way to go.

If your community would involve guppies and neon tetras then a tank of 60cm or larger is a good start. If you want gouramis or angelfish then you’ll need a 90cm tank and if you want a Clown loach or silver sharks the tank would have to be larger still. 

Aquariums are very heavy so any tank over 40 litres in volume really needs a dedicated stand or cabinet to sit on. And if you’re considering a very large aquarium first see if it would fit through the door! Check the floor is strong enough and recruit friends and family to help you lift it into the house. 

The bigger the tank the better as it will enable you to keep more fish, and larger bodies of water are more stable. Large tanks do cost more to run however and need larger, more expensive equipment. 


Aquariums come in all shapes and sizes although a rectangle is the most popular and the most practical. Tall fish suit tall tanks so 60cm high tanks are best for Discus and Angelfish and shallow tanks are best for loaches and catfish, which stay on the bottom. How long are your arms? Could you touch the bottom of a tall tank to clean or decorate it? Is a hexagon or a sphere more your thing? Or a cube? There’s a tank to suit everyone, but not all suit certain types of fish like those that need lots of room to swim up and down, like Redline torpedo barbs. They need a long tank. 


Where you place the tank is important. It needs to be out of direct sunlight as that causes algae, but also away from radiators (overheating,) and doors (draughts.) Areas, where lots of people come past, can spook fish and avoid loudspeakers and vibrations. Is the floor strong enough for a big tank, and are there power sockets near but not under the tank? A typical tropical aquarium will need three power sockets for the light, heater and filter, but some may need six if multiple lights and filters are used. Place the tank away from the television but in front of a chair so that you can sit and enjoy the fish. That’s what it’s all about after all.

Open topped or with a hood?

Aquariums are available rimless - an open-topped tank where lighting is clipped on or suspended, or with a hood, where lid flaps are included and lighting is typically built-in underneath. Open topped tanks can look modern and minimalist and allow for the user’s specific choice in lighting, although fish can and do jump out of them. Hoods can restrict access sometimes but they stop dust getting in and fish getting out. They keep noise and evaporation in too and are the most popular choice for tropical aquariums. 

With or without equipment? 

If you’re unsure which light, heater and filter you need, opt for a package that comes with equipment or even a tank where lighting, heating and filtration is built in. It takes the guesswork away and the manufacturers have already selected suitable equipment for that size of tank for you. As you become more experienced you may wish to change out equipment or specialise, in which case a bare tank may be better for you long term, where you can equip it with the filter and lights of your choice or even upgrade as your fish grow. 

Other choices

Would you feel safer with an acrylic fish tank? Or do you want a tank that you can just decorate, fill up and plugin with the minimum of fuss? Black or clear silicone, standard glass or super clear low iron glass? Do you want a tank to match your furniture or do you want a tank that you could upgrade to saltwater in the future? 

See the full range of aquariums available to you here. 

Tropical fish tank equipment list