These nutrients include nitrates, sulfates and phosphates. Macro nutrients should never need to be added to the water of the tank. They exist on their own. Micro nutrients are needed in very small amounts. Copper, iron and zinc are among the micro nutrients live plants will need to survive in the aquarium. Using a siphon hose, remove 20 to 25 percent of the water from the tank. Always make sure that your chemical balance is correct. High levels of chlorine and ammonia will cause death. Cleaning the filter should be a monthly task as well as changing the filter cartridge. Be sure not to clean the filter too thoroughly as it contains helpful bacteria that aids in stabilizing the chemical balance in the tank. You will need a tank, some sort of filtration system, lighting and some basic cleaning tools. The plants are fairly easy to care for, but you do have to keep up with your regular maintenance. Synthetic plants may be a good alternative to live plants, if you are not willing to make the investment in live plants. If a particular fish lives on a coral reef, try to incorporate that into the grand scheme of the aquarium. Stress can be minimized by providing ample opportunities for fish to act normally. Lastly try to avoid overcrowding the tank. This is another common problem that can be easily avoided. A general rule of thumb is one small fish per every ten gallons of water. As with any new hobby, especially one that involves living creatures, always consider the maintenance that will be involved. If you care for your aquarium properly, you will be sure to have happy and healthy Goldfish for many years. Goldfish have a life expectancy of five to ten years. If you do a good job maintaining their fish tank, you should have fun, beautiful fish for a long time. Begin by adding only three to four small fish. A general rule is to wait another thirty days before adding additional fish, because that is the incubation period for most fish illnesses. In addition, test the nitrite and ammonia levels before adding these additional fish. The ammonia levels should return to zero.