Any excess food will become debris in the tank and lead to illness or attribute to excess nitrite levels. You should check the water ph and temp weekly. Any necessary adjustment should be made promptly. Check with your local pet store when purchasing fish to find out what levels are appropriate. They vary amongst fish species. The floating plants will provide this escape for the fish and will add a pleasing effect to the design and decoration of the aquarium. Once your plants are established and growing well, add the fish of your choice and enjoy a beautiful tank. While keeping live plants in the tank, it is important to care for them as you would any other plant. 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. Generally, the water and the fish in the tank will provide the nutrients and fertilizers needed for plant growth. 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. This bacteria is actually essential to maintain a healthy and balanced aquarium. On a weekly basis, any waste should be removed from the surface of the gravel at the bottom of the tank. Using a siphon tube will accomplish this. If water is removed during this process, be sure to replace it and keep the water in the tank at the same level. Add chemicals and chlorine weekly so the balance within the tank remains the same. Check with the supplier for compatibility before combining tropical invertebrates. Unlike their tropical counter parts, cold water invertebrates are usually not sold in stores. They have to be collected from tide pools. It is important to make sure that these species are not on the endangered species list before removing them from their home.