Saltwater Aquarium Basics

Keeping a saltwater aquarium is not as difficult as many people believe, it's just a little more involved. The following is a very basic overview of how to set-up and maintain the beginner saltwater aquarium.


The first step before you run out to purchase an aquarium for saltwater is to do a little homework. Take the time to think about what kinds of fish you would like to keep, because this will effect everything from tank size to feeding. Be sure the fish you want to keep will make good tank mates and be aware of their adult size. Keeping up with fish information will help prevent losses.

Aquarium Size

The smallest recommended size is a 30 gallon aquarium, and for saltwater, bigger is always better. A large marine ecosystem can better handle the daily fluctuations in water quality than a small ecosystem. We have found that 55 gallons is a perfect beginner aquarium size. A 55 gallon tank will allow for several types of fish and it is large enough to maintain a stable environment. Keep in mind, that while it is possible to keep a very small saltwater tank, we recommend that only those aquarists with prior saltwater experience attempt it.

Setting Up Your Aquarium

The basic equipment for saltwater is the same as for freshwater with a few extras:

-You will need good filtration, be it a hang on power filter, a canister filter or a wet-dry system. You will also need a protein skimmer to remove organic waste. Check with one of our knowledgeable staff members, as these types vary with the size of aquarium desired.

-Substrate should be crushed coral or any coralline type gravel. This helps maintain a proper pH of 8.3, and provides a good base for rock.

-Salt mixes are available in several brand names. Mix your saltwater directly in the aquarium when first setting up. Follow the mixing directions on the package and check the salinity with a hydrometer. Salinity (or specific gravity) should be between 1.020 to 1.024 for fish-only system and between 1.022 to 1.026 for reef tanks.

-A heater is required, set your temperature between 75 and 82 degrees.

-Be sure you have test kits on hand to monitor your water chemistry. Test the water in your new aquarium at least twice a week for pH, Ammonia, Nitrite and Nitrate.

-Lighting is another requirement, but how much you will need varies. An aquarium with only fish requires no special lighting, but if you are interested in keeping living corals it is necessary to provide bright lighting for the corals to thrive.

Cycling Your Tank & Adding Fish

Before adding your favorite fish, your tank must "cycle" or become biologically stable. Cycling is the process where a nitrifying bacteria colonizes on the rock and in your filter. This bacteria's job is to detoxify the wastes created by your fish. You will notice that within the first few weeks by testing your water, ammonia and nitrite levels will rise in the tank and slowly decrease. Also during this time you may see the water in the aquarium start to cloud or look grey. Do not worry, this is natural, the cloudiness will pass quickly on its own or you can add a bacteria supplement such as Stress Zyme to help lower ammonia levels and aid in the cycle.

The cycling process can be very stressful for most fish. We recommend that you begin with hearty starter fish. For saltwater, we usually recommend Damsel fish which come in a variety of colors and sizes. Sometimes, however, damsels can be aggressive and may need to be removed at a later date if you wish to keep docile fish. Black Mollies can also be used as a marine starter, with no problems of aggression. These starter fish will cycle or condition your aquarium and filters.

While your aquarium is cycling do not change any water, clean out your filter media, or add more fish. Your tank will be completely cycled when ammonia and nitrite both test at zero levels and nitrate tests low. This can take anywhere from 3 to 8 weeks. The key here is to be patient.

Fish & Maintenance

your aquarium is cycled, add new fish gradually. Adding too many fish at once can disrupt your cycle and increase the possibility of problems with the tank. Be sure to follow recommended acclimating procedures to ensure a happy addition.

Once cycled, basic aquarium maintenance includes feeding, cleaning and water changes. When you purchase your new fish, find out what food is best and how often they should be fed. Saltwater foods are available in dried and frozen varieties and each type of fish has different needs. Cleaning includes scraping aquarium walls to keep them free of algae and siphoning the gravel on a regular basis. Many small animals like hermit crabs and snails will help keep algae to a minimum as well. Water changes are crucial to keeping your tank healthy. Never change more than 25% of the aquarium water at one time. Changing too much can do much more harm than good. Normal water changes should be done approximately every 14 to 18 days. This keeps nitrate levels in the aquarium below 20ppm and ensures healthy fish and invertebrates. Always pre-mix your saltwater in a container before adding it back into the aquarium and make sure the temperature and specific gravity is equal to that already in the aquarium.

With this basic information you are well on your way to being a marine hobbyist! If at any time you have any questions or need help selecting fish or supplies for your aquarium, feel free to contact the fish room at 717-299-5691 ext. 1213 or You can also find informative articles on That Fish Blog at or post your questions on our Facebook page. We at That Fish Place - That Pet Place want to keep you and your fish happy for years to come!

Recommended Products:

Salt Mix
Sand or Substrate
High Output Lighting
Wet/Dry Filter
Protein Skimmer