How to Start a Freshwater Aquarium the Right Way

Research which species of fish you wish to keep, preferably before buying your tank and equipment. Among the hardy species suitable for beginners are small tropical fish such as guppies and larger coldwater fish such as goldfish. Acquire a tank large enough for the fish. Bear in mind that, even if you wish to keep small fish, larger tanks are more stable and easier to maintain. A tropical community tank is a colorful option and straightforward to look after if you choose hardy, compatible fish.

Rinse the tank with plain water. It might be easiest to rinse the tank outside with a hose or in your bathroom tub.

Situate the tank on a stand or piece of furniture strong enough to hold its weight.

Position the heating system, if you are using an under-gravel heater. If you have a cheaper immersible or submersible heater, wait until later.

Rinse the gravel and any rocks in a bucket to remove dust and grit.

Lay the gravel on the bottom of the tank with the rocks positioned according to your taste. Position the filter and an immersible or submersible heater, but do not switch them on.

Fill the tank with dechlorinated water. You can dechlorinate tap water by leaving it in buckets for 24 hours. Alternatively use a commercial dechlorinator according to its instructions.

Switch on the heater and monitor the temperature, adjusting the thermostat as necessary. Most tropical tanks should have a water temperature of about 75 to 85 degrees Fahrenheit. Also switch on the filter.

Add aquatic plants after a day, to allow the tank to settle. Use the handle of an aquarium net or your hand to bury, then cover, their roots in the gravel. Switch the light on and have it on for 12 hours a day thereafter to support their growth.

Add a culture of nitrifying bacteria, available from aquarium supply stores. This speeds up the cycling process. A couple of fish flakes give the bacteria something to feed on before the arrival of fish. Normally, the bacteria process fish waste and other organic materials in the tank.

Introduce fish, two or three at a time, switching the light off first to calm them. Begin introducing fish after the tank has been cycling for at least a week. This allows the nitrifying bacteria, which are essential for a healthy tank, to become established. Allow the plastic bag the fish came it to float for at least half an hour before you release them. Try not to let too much bag water enter the tank. Add more fish every couple weeks or more until the tank is fully stocked. You can have a maximum of 1 inch of fish for each gallon of water in a coldwater tank and 2 inches of fish per gallon in a tropical tank. Base your measurements on the maximum adult size of each fish, not the length they are when purchased. It is best to slightly understock.