A beginner’s aquarium set-up checklist: from bowl to tank

A well-planned aquarium is one of the most rewarding things you can bring into a home, and most early disappointments come down to rushing the start. This checklist takes you from choosing a tank or bowl through to the day your first fish arrive. ArdentPets sells aquarium equipment only, never live fish; when you are ready for fish, buy them from a reputable aquatic retailer who can advise on which species live well together.

1. Choose the fish before the tank

It sounds backwards, but the fish you would like to keep decide everything else. Their adult size, how active they are, whether they live in groups and whether they need warm water all set the minimum volume and equipment. Goldfish, for example, grow far larger and produce more waste than many people expect, so a small bowl does not suit them. Small tropical species that live in shoals need room to swim together. Make a short list, research each fish, and then choose a tank that gives them space as adults.

2. Bowl-style aquarium or rectangular tank?

• Modern bowl-style aquariums with built-in filtration and lighting look striking on a sideboard and are well suited to a small number of carefully chosen fish. Older-style open glass bowls without filtration are a different thing and are best avoided.
• Rectangular tanks offer more swimming length, more surface area for oxygen exchange and more stable water. In general, a larger volume of water is more forgiving, because changes happen more slowly.

3. Pick the spot before it arrives

Water weighs roughly one kilogram per litre, before you add gravel, rock and glass, so the aquarium needs a level, sturdy stand or cabinet designed to take its full weight. Keep it out of direct sunlight, which encourages algae, and away from radiators, doors and draughts, which cause temperature swings. You will also need a power socket close by, and enough space above and around the tank to reach in for maintenance.

4. The equipment list

• Tank or bowl-style aquarium, with a lid or cover
• Filter rated for the volume of the aquarium
• Thermostatic heater, for tropical fish
• Thermometer
• Lighting suited to the tank and any live plants
• Substrate, such as aquarium gravel or sand, rinsed before use
• Décor and hiding places, such as aquarium-safe rocks, wood and plants
• Water conditioner, to make tap water safe for fish
• Water test kit covering ammonia, nitrite, nitrate and pH
• Gravel cleaner or siphon, a fish net and a bucket used only for the aquarium

5. Fill it, then let it mature

This is the step most beginners skip. A new aquarium does not yet contain the colonies of beneficial bacteria that live in the filter and break down fish waste. Ammonia from waste is converted to nitrite and then to the far less harmful nitrate, but only once those bacteria have built up, which typically takes several weeks. During this time, keep the filter and heater running and test the water regularly. Your aquatic retailer can explain how to feed the bacteria while the tank matures without fish. When ammonia and nitrite consistently read zero, the aquarium is ready.

6. Add fish gradually

Start with a few fish rather than the full list, and add more over the following weeks so that the filter can keep up. Float the bag in the tank for a short while to let temperatures equalise, follow your retailer’s advice on acclimatising, and keep the lights low for the first evening.

7. A simple weekly routine

• Change a portion of the water each week, commonly 10 to 25 per cent, using conditioned water at a similar temperature.
• Siphon debris from the substrate as you go.
• Rinse filter sponges in old tank water rather than tap water, so that the bacteria survive.
• Test the water now and then, and wipe the glass.
• Feed small amounts that are eaten within a couple of minutes.

8. Electrical safety

Water and electricity need respect. Leave a drip loop in every cable so that water running down it cannot reach the socket, plug equipment into a socket protected by a residual current device (RCD), and always unplug the heater and filter before putting your hands in the water.

Ready to plan your set-up? Browse fish and aquatics and habitats and housing. If you keep small animals too, our guide to setting up a hamster or gerbil home may help. Delivery costs nothing anywhere in the UK, and you have 30 days to return unused items free.