Your fish will enjoy having the light, so it is probably best to buy a hood that includes a light. Try to keep the tank out of direct sunlight when you choose it's position within your home. This will also add to algae growth. Once you have your tank set up and the water is stabilized, you may add your fish. In an established aquarium there are certain bacteria that help the breakdown of ammonia to nitrates, but they are not present in a new tank because they are generated from existing fish. If there are no existing fish, then there are no good bacteria. The basic principle of the nitrogen cycle is this. Maintenance is a necessity and you will need to clean your tank at least once a month. It is best to try to clean the tank as often as every two weeks however, don't over clean your tank or you will remove some of the beneficial bacteria. Most people think that removing this bacteria is a good thing, but it's the exact opposite for a saltwater tank. The tail itself is usually about one third of the size of the whole fish. It is possible to mix guppies with other varieties of fish. However be careful when mixing because, guppies are targeted as easy prey due to those fancy tails. Guppies breed very quickly, usually about every three to four weeks. Certain invertebrates feed on certain fish, and the reverse is also true. Therefore, it is important to research the species carefully to ensure that you do not put predator and prey together in the same aquarium. Diseases can also spread more rapidly and are more difficult to prevent and cure in aquariums containing both invertebrates and fish species. These first two questions are the key to maintaining your aquarium allowing you to enjoy this beautiful addition to your home. When should I clean my tank? You should clean your tank once every two months unless you can really tell it needs cleaned before then. Why should I clean my tank once every two months?