How to Make a Saltwater Fish Tank

Determine the size tank you want. Smaller saltwater tanks are actually more difficult to maintain, so you should start with at least 15 gallons if this is your first time. Researching the type of fish you want also will help you decide on the appropriate size.

Clean your tank using water only. Do not use soaps or cleaning products, as they can leave residue that is dangerous to fish. While you have water in your tank, check to see if there are any slow leaks. If there are, do not use the tank.

Place your clean tank on a tank stand. The stand should be made for the size and potential weight of your aquarium to avoid accidents. When in doubt, ask an employee at your local pet or fish supply store about the size of stand you need. Place the tank away from direct sunlight as well as heating and air vents, all of which could affect the temperature and light of the aquarium.

Paint the outer, backside of your tank a dark color, such as blue or black. Allow the paint to dry for a full day. Paints make the fish stand out against the dark colors. If you prefer, you can use a printed background; however, make sure you fully tape the top of the background to the tank to keep salt from getting between the tank and background.

Set up your heater, filter and protein skimmer. Avoid under-gravel filters, which are not necessary. Follow the package directions when setting up your equipment.

Fill a 5-gallon bucket with tap water at room temperature. Pretreat the water by adding an additive that removes chlorine and chloramines according to package directions. You can find these at your local pet supply store. Add a store-bought salt mix to the bucket according to the package directions. Stir the bucket with a hydrometer and check the specific gravity of the water. You are looking for a reading between 1.021 and 1.024.

Add the pretreated water to your tank. Repeat Steps 6 and 7 until your tank is filled with treated water.

Plug in all your equipment and allow it to run for an entire day.

Choose a live rock or several rocks for your tank. Place your chosen rocks into the center of the tank. Point the power heads from your filter toward the rocks and allow loose debris to be blown off. Use a siphon to suck off the debris.

Turn off your filter and protein skimmer every four days. Use a toothbrush to scrub the surface of your rock to scrape off dead organisms, which you can siphon off. After siphoning, refill your tank with more pretreated water that is prepared as directed in Step 6. The only difference in the water preparation is it should be done a day in advance to ensure you have the same specific gravity as you have in your tank.

Repeat Step 10 every four days until you have no ammonia or nitrites in your tank and your nitrate reading is very small. Be prepared for this to take up to several weeks. During this time, you may notice an odor emitting from your tank, which should go away once you reach these readings.

Repeat Step 6 and leave the bucket to sit for a day. Add the substrate you want to use into your bucket and mix it up. Use a siphon to remove any debris that appears. Scoop your substrate out with a plastic cup and add it to your tank. If it falls on your rocks, spray it off using the power heads. Adjust the water level as necessary.

Allow your tank to sit for the next three to four days. You are looking for a set of specific readings before proceeding. Your temperature should be between 75 to 80 degrees Fahrenheit, a specific gravity of 1.020 to 1.024, a pH of 8.0 to 8.4, a nitrate of at least 20 ppm or less, carbonate hardness of 7 to 10 DkH, and your ammonia and nitrites should be 0. Your local pet store carries testing kits which you can use to determine these readings.

Choose fish to add to your tank. Add only one to two fish at a time for best results. Condition the fish before adding them to the tank by placing the fish and the water from the bag you brought them home in into a 5-gallon bucket. Add 1 cup of water from your tank to the bucket. Add an additional cup after 10 minutes. Continue to add water in this manner for the next hour. After the hour, use a net to move your fish from the bucket to the tank. Discard the water in the bucket. Do not feed your fish the first day. After a few days, it is safe to add an additional fish.