It is best to add fish later, and slowly as to make sure the salt balance in the tank is correct and remains that way. At this time, you can add a variety of snails or crabs if you wish to have them part of your tank. You will also need to install a protein skimmer. The tank should be functioning as if it were full of fish. In addition, there are vitamins that can be added to the foods to replace any nutrients that may have been lost in the freezing or drying processes. Just as we humans don't like to eat the same thing every day, neither do fish. Keep a variety of food handy because they will not eat the same food daily. Monthly Cleaning Routine Finally, some monthly steps will assure that your aquarium stays clean and healthy. A partial water change should be performed each month. 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. Once your plants are established in a clean, well lighted tank, you must care for them by making sure they receive the nutrients required for healthy growth. Plants need both macro- and micro nutrients. Macro nutrients are usually found naturally in tap water and in the fish themselves. These nutrients include nitrates, sulfates and phosphates. Home aquariums were generally kept only in coastal towns where the fish were readily accessible. Today, however many things of changed. We wouldn't dream of dipping a net into an aquarium and frying up the family pet for dinner. That's what Red Lobster is for. Home aquariums are for our personal entertainment and enjoyment. The proper way to change water in a tank is to do it gradually. First unplug any lights and equipment before cleaning the aquarium. Change approximately one third of the water in the aquarium every one to two weeks. Water from the tap should be treated accordingly before adding to the tank and adjusted within two degrees of the aquarium.