Fish are beautiful and peaceful pets, and in general are low-maintenance. However there are a few things you need to prepare before bringing your new fish home.

Due to an excess of chlorine and gases, most tap water is unsuitable for aquariums, and needs to be conditioned before introducing your fish. Conditioning, or aging, is done simply by letting the water stand in its tank for at least one week. This allows the water bacteria to strike its own balance, kills possible fish parasites, and lets organic particles settle out.

During the conditioning process, the tank water will become cloudy due to an increased bacterial count. The bacteria will die out and the water will become clear within a few days. There are several chemical mixtures on the market to remove chlorine from the water, and bacterial cultures that can be added to the water to achieve the desired balance sooner. You may also find commercial ph stabilizers that, when added to tank water, reduce the need to change tank water so frequently. Check with your veterinarian or fish provider to see which of these mixtures is right for your fish.

The species of your fish will determine the exact temperature your tank needs to be. Higher temperatures mean a high bacteria count and reduced dissolved oxygen. Any sudden temperature changes may cause a shock in your fish, so a stable aquarium heater is a good idea. These can be attached to the side of your aquarium. You will also need a thermometer. Some thermometers float inside the tank, while others attach themselves to the glass outside.

A successful aquarium needs at least 12 hours of light a day. Natural light is probably sufficient, as long as the tank is not in direct sunlight, but an artificial light may be required at times, particularly to control plant and algae growth.

Locating your aquarium near a window is desirable, as long as the tank is not in direct sunlight. Similarly, placing your tank near a radiator or heater will overheat the aquarium—and the fish. These locations should be avoided, as should any particularly drafty areas or places near air conditioner vents. Your tank needs a stable temperature that is neither too warm nor too hot.