Only in combination with some larger Cichlids can there be a problem as the Cichlids tend to extend their territorial claim to the entire tank. The one thing to consider before adding a catfish to your existing aquarium set-up is the size of the other fish. While catfish generally get along with most fish, they are a predator and will attack and feed on smaller fish. The process may seem to take a long time, and because of this, many people opt to use fake coral instead. However, the time spent waiting will be well worth it when you are later able to display your own coral aquarium. If you follow some simple steps and have patience for about 12 weeks, you will be able to create and own your piece of underwater paradise. This may seem silly, but the main cause of sickness in fish is stress. So, a happy fish is a healthy fish. Check to see that all lights and filters on the aquarium are plugged in and functioning correctly. Feed the fish daily. Only feed what can be consumed in the first two to five minutes. Any excess food will become debris in the tank and lead to illness or attribute to excess nitrite levels. 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. Another cause of stress in fish is overcrowding. Make sure there allow about ten gallons of water per one inch of fish. Account for the full grown size of the fish, not the size of fish when it is purchased. They are all cared for in the same way, so they will be referred to as bubble coral throughout the rest of the article. One of the most important things to know about your coral is how to space them when you add them to the tank. Bubble coral have long tentacles which are armed with stinging cells. Mostly, they remain retracted until nightfall, when they are extended to aid in feeding habits. You will need a heater for temperature control, and a thermometer for checking the water temperature. It will take approximately five bags of rock or other substrate to line the bottom of the tank. Choose a bright color to add some interest to the aquarium. In addition, you will need to purchase a filter for the tank.