They are the hardiest of reef species, and who wouldn't love to have Nemo swimming around in their living room? Monitor the marine life closely. Check the activity levels of the fish, and watch for stress. Stress is the most common cause of sickness in fish. Remember that these creatures may have come directly from the ocean, and it may take a while for them to get acclimated to their new home. These sharks are found all over the Atlantic Ocean, and are the most common type of shark. Although these sharks would seem to be the perfect aquarium kept fish, because of their smaller size, they are not. They still grow to reach an average length of about five feet, and can weigh as much as three hundred pounds. There are group and schooling catfish that get along well with each other. There are also loners who always stay away from their neighbors. Catfishes are the ideal candidates for community tanks because they inhabit niches and shelters on the bottom not occupied by other aquarium inhabitants. They generally get along well with all types of fish. Live plants should be pruned weekly. Dead or broken leaves should be removed daily. A live plant aquarium will require the same basic equipment needed for an aquarium containing fish. The basics are as follows. You will need a tank, some sort of filtration system, lighting and some basic cleaning tools. Start by replacing the gravel into the tank, followed by refilling the water. Take notice of the temperature once again. Try to add water that is of the same temperature as the original water in the tank. Add your finishing touches with decorative pieces, then carefully move the fish back in. It may take a little while for the fish to adjust to the new water, but after having followed all these steps, you can be sure that your tank is clean and healthy. 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. This also takes about a month. There are a few basic tips that will keep fish healthy.