between 8-8.4 and a salinity content of 1.024-1.025. Luckily they do eat the same food. They feed off of a diet of small pieces of raw fish, shrimp, squid and mussels. When keeping cold water invertebrates such as the species mention above, it is a good idea to keep a separate tank full of shrimp, mussels, and scallops to be used as a food source, if you wish to use fresh rather than frozen foods. This cuts costs when setting up your first tank. It also makes the aquarium much easier to maintain in the long run. Keep in mind that only certain coldwater fish can survive in a tank without heat. Most common are goldfish and guppies, but there are a multitude available and you will be able to have an array of fish living in your coldwater tank. That being said, it is not necessary to be an expert in order to maintain a saltwater aquarium. Just as with freshwater fish, there are some saltwater species that are hardier than others. There are a few basic needs that if met will ensure that the fish are cared for properly. The most important need that any creature has is the need for food. A fish lover can choose from small cylinder shaped tanks that can double as a coffee table lamp to wall huge wall sized aquariums. While, there are some basic things that will be included in most kits, such as, a filter, some substrate or coral and sometimes lighting, the kits themselves can vary greatly. When cleaning the tank, you will need remove of stir the gravel to remove sediment that could possibly change the chemical make up of the tank. Use caution when cleaning an acrylic tank and be sure that the cleaning supplies being used will not harm the tank in any way. The best thing to use to remove algae is phosphate drops. They usually grow to be about a foot long. They will still need a larger tank with plenty of space, because they too will have a cruising nature. These fish, like true sharks will eat just about anything that will fit in their mouths. Therefore be careful not to house it with smaller fish. The catfish shark should be kept in a tank with brackish water.