Saltwater fish tanks are beautiful and can include fish, coral, sea invertebrates, and other marine life. While many people like the idea of having a saltwater tank, they are much more difficult to set up and take care of than a freshwater tank. With patience and the right know-how, though, you can set up and maintain a saltwater fish tank without too much stress.
The size of your saltwater fish tank is very important, because saltwater fish need a good amount of room to live comfortably--more room, in fact, than freshwater fish do. The typical ratio between water and fish for a saltwater tank is 1 inch of fish for every 3 gallons of water. What this boils down to is the basic starting fish tank for most people should be able to hold about 50 gallons. When you start putting together your plans for your tank, think about what kind of fish you're going to have in it. Larger fish will, of course, require a much larger tank.
Just as saltwater tanks need to be bigger for the fish living in them than freshwater tanks, they also require more equipment and additions to work properly. The equipment you need to start a saltwater aquarium is a heavy-duty spectrum lighting bulb or system, a protein skimmer, live rock and argonite sand on the bottom, a water pump, a hydrometer, salt mix, and a basic test kit that will tell you about the levels of salinity, ph, and chemicals in the tank.
If you are planning on putting a reef aquarium together, then you need to pay even more attention to setting up your tank. Reef aquariums focus not only on fish, but also on corals and invertebrates. The first thing that you must make sure of is to get the right light. Most tanks need a fish-only light, which is common and cheaper than reef lights. You should use power compact and metal hallide lights in these setups, because corals (especially hard corals) and certain animals like clams and anemones love and require more light. In general, you will have to test the water more often and clean the tank on an almost daily basis as well.
If you hadn't guessed already, the salinity levels of a saltwater tank are incredibly important to keep in check at all times. You need to maintain a strict balance to see to the proper health of your saltwater critters. This is what the hydrometer in your tank is for. It will keep track of and help to level out salinity. The ideal level will be 1.022, but anywhere between 1.020 and 1.030 is acceptable. As water evaporates, you need to make sure to add commercial salts with water to maintain balance.
The nitrate cycle is an important natural cycle that will keep the creatures in your saltwater tanks healthy, as long as you know about it. When fish excrete ammonia as waste, it can build up to toxic levels. Over time, bacteria transform this into less toxic substances. It usually takes about 4 to 6 weeks for this cycle to form, and during that time you shouldn't add fish to the tank, or ammonia could become overwhelming. Certain small fish, such as any variety of damsel, is a good choice to add when a cycle is forming.