What Is Absolutely Needed For A Saltwater Fish-Only Aquarium

(besides the livestock)

The 16 products you definitely need,
the 3 you might need, and the decor you probably want

You want a saltwater fish-only aquarium. What do you need to put fish in the aquarium with a reasonable expectation that they will survive and thrive? Here are the 16 essential products you need for a saltwater fish-only aquarium.

With a quality filter, you will need to do less work cleaning your tank. For tanks under 40 gallons, a simple hang-on Power Filter or Canister Filter is perfect. For larger tanks, a high-quality protein skimmer is the best solution. We recommend the protein skimmers from Reef Octopus, IceCap, Simplicity, and Tunze.

Our protein skimmer section organizes skimmers by tank size and where the skimmer is located (hang-on back, in-sump, or in tank). A sump is a great place for a protein skimmer because it keeps it out of view. If you don't have a sump, you can use a hang-on-back skimmer.

Some “complete” nano tanks, such as the Coralife BioCube, have a filtration chamber built into a back compartment of the aquarium. It includes space for a small protein skimmer.

Fish-only aquariums don't need as much light as reef aquariums. The fish need very little light. However, you may want to have a brighter light so you can better enjoy your aquarium. Refer to the Fish Only Tanks Lighting Chart when choosing a light.

LED lights will save you money because they are energy efficient and you won't need to change the bulbs. They should last five to ten years, although with some cheaper LED lights you might see earlier failure of individual LEDs.

Testing ensures your water is safe for your fish. When you first set up a tank, test for ammonia, pH, nitrite, and nitrate. The Aquarium Pharmaceuticals Saltwater Test Kit includes these four tests.

Once your tank is set up and running, the pH and the nitrate tests will be the most important. If your nitrates are 20 ppm or above, you should definitely do a water change. If your pH drops below 7.8, you need to add buffer (see the Aquarium Buffer section for buffer use).

You will need to test your saltwater's salinity. The Coralife Deep Six Hydrometer and MarineAndReef.com Reefractometer (aka Refractometer) are good choices. You will also need an aquarium thermometer.

Clean your aquarium to keep it healthy and attractive. For maintenance, you will need a good gravel vac and algae magnet. The Python Gravel Vacs and the Flipper Magnet Cleaners are good choices. When choosing a gravel vac, consider your aquarium depth; when choosing an algae magnet, consider your glass thickness.

All of the aquarium salts we sell are high quality. For smaller tanks, we recommend the Two Little Fishies AccuraSea1 because it comes in five-gallon packets, making it easy to mix saltwater in five-gallon increments. You might consider the Two Little Fishies Small Saltwater Aquarium Salt Mixing & Water Change Package for smaller reef aquariums.

Start mixing saltwater with RO or RO/DI water. You can buy the water at your local fish store or grocery store or make your own using an RO System. Ideally, use an RO/DI system (DI stands for deionization) instead of just RO (reverse osmosis). If you insist on using tap water, we don't recommend it. But if you do, be sure to dechlorinate the water using a product such as Seachem Prime.

Most saltwater aquariums have tropical fish, and you will probably want to create an environment that looks appropriate for tropical saltwater fish.

You will want some sand. We recommend using an aragonite sand substrate. CaribSea Florida Crushed Coral and CaribSea Seafloor Special Grade Reef Sand are good sand substrate choices.

Most people with saltwater fish-only tanks have some rock structure. You can use either live rock or dry rock. Live rock is critical in a reef aquarium as it helps with biological filtration. This biological filtration is also helpful in a fish-only aquarium. Live rock is harvested from the ocean, and you can buy it locally. Dry rock is cheaper than live rock, and it's easier to create interesting structures with dry rock. You can use Two Little Fishies STAX Rock or CaribSea LifeRock Shapes. You will need coral/coral rock adhesive to glue your rocks together.

You will notice our website has hundreds of different aquarium additives. The good news is that most of these are for advanced aquarists looking for specific results. Reef aquariums need additives that fish-only saltwater aquariums do not require. Most aquariums with sufficient water changes just need pH buffer. Add buffer as needed after testing the pH. The Brightwell Aquatics Boost PH Plus is a good choice.

Water movement is important in fish-only tanks to oxygenate the water and stir up the waste so the filter can remove it. As a general rule, you want enough water movement to turn over your aquarium’s total water volume at least 6 to 7 times per hour. More is better. To calculate total water turnover, add the flow of all the pumps in your system.

With the Coralife BioCube and other integrated nano aquariums, a circulation pump is in the back chamber. You can add a powerhead in the tank to increase flow.

Tanks without a back chamber or a sump will require powerheads inside the tank. We recommend using two—one in each corner. The Hydor Koralias are great choices.

Larger aquariums with sumps can count the return pump flow from the sump, but they may also require powerheads in the tank for additional flow if the return pump volume is not at least 6 to 7 times the tank volume. We have large aquarium pumps from Iwaki, Lifegard, and Reeflo. DC pumps, such as the Reef Octopus Controllable, are very energy efficient.

Saltwater aquariums need to be between 76-82 degrees. You will need a thermometer to know your tank temperature.

If the room where your aquarium is located stays around 75-80 degrees, you probably will not need a heater or chiller. These days, with low-heat LED lights and DC pumps, chillers are less common. Still, if you keep the room with your aquarium above 80 degrees, you will probably need a chiller (the equipment will raise the temperature above the 82-degree threshold).

With chillers, we highly recommend getting a bigger chiller than you absolutely need, since it will not cost much more. In the event of a heat wave or an air conditioner failure, that extra capacity may save your aquarium’s inhabitants.

If your aquarium temperature drops below 76 degrees at any time, you will need a heater. All the heaters we carry have aquarium-size ratings. Keep in mind the rating assumes you only need to raise the temperature by 10 degrees.

Your home may have GF/CI outlets, but if it doesn’t, you may want to install one for your aquarium equipment.

This really depends on the type of fish you purchase. Ask at the aquarium store about the best food for the fish you purchase.

If you travel and no one is at home to take care of your fish, you might consider an automatic fish feeder.

Always use a fish net to move fish you buy at the aquarium store.

For help getting your tank started, we recommend reading the Coralife LED BioCube Aquarium Setup Guide. The guide is specific to the Coralife BioCube (and it shows how to set up a tank for corals), but most of the concepts apply to all saltwater aquariums. We also include links to videos we produced to help with cycling your tank, adding livestock, and more.