If you add too many fish at once to a new fish tank, the water will not be seasoned enough to dissipate it. As the water in your Goldfish tank ages, it builds up beneficial bacteria that turn harmful chemicals excreted by the fish into harmless ones. However, this will take some time. Start out with only one fish. Before purchasing fish, the aquarium must be cycled. This could take anywhere from twenty four hours to four weeks. 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. An example of a specialty aquarium would be an aquarium full of sea horses. Sea horses should not be kept with any other type of fish or marine life, because they are timid and slow eaters. Their food source could easily be taken away by other tank mates. Seahorses prefer to swim vertically rather than horizontally, and should be placed in a tall tank. Now at week 6, you will add your first pieces of coral. There are many types of coral used in saltwater coral aquariums. Some of the most common are Button Polyp, Yellow Polyp, Hairy Mushroom Coral and Bullseye Mushroom Coral. Make sure when adding your coral, it is attached to the live rock at the bottom of the tank. During the monthly cleaning, scrape and remove all algae from the surface of the tank. If you find you are having a significant amount of algae, consider adding an algae eater to the tank. Should you already have one, be sure to keep an eye on the temperature of the tank and you may also want to limit the time in which a light is used. When planting these, remember to allow plenty of room for growth. The roots will grow outwards and require additional space. Another type of aquatic plant is known as cuttings. These plants may be transplanted from other thriving plants, without have to root them. Cuttings should be planted individually.