Precise Amount of Salt Needed for a 55 Gallon Saltwater Tank

55 gallon

In the past, saltwater aquariums were considered mysterious and difficult to maintain. That might be true then, but that’s no longer the case today. The marine aquarium hobby continues to enjoy growing popularity due to the development of high-quality support equipment and products, as well as a better understanding of the needs of marine organisms and their care. This has led many freshwater enthusiasts and beginners to try saltwater aquarium storage.

Marine aquarium owners should aim for a salinity of 35 parts per thousand. This means that for every thousand grams of freshwater you should add 35 grams of salt or 133 grams of salt per gallon of water or 1/2 cup of salt per gallon.

Therefore, the amount of salt for a 55-gallon saltwater tank is 7,315 grams of salt or 27.5 cups for your 55-gallon saltwater tank. 


salt for saltwater tank

Note: You need a hydrometer to measure the level of salinity in your tank after the addition of salt. Having a hydrometer is a must. Hydrometer cost less than $10 depending on the local store.

Starting with a saltwater aquarium:

While the marine aquarium hobby is more expensive than freshwater, you can start with a basic fish-only setup and evolve into live invertebrates and corals depending on your budget and experience. It is important to understand a few additional things about water chemistry to manage a saltwater aquarium, but the basic principles of aquarium conservation are essentially the same for freshwater and saltwater.

Saltwater sources for fish and coral aquariums

1. Saltwater from a nearby ocean


take water fron ocean

The ocean is a great place to get natural seawater for a saltwater reef aquarium, but it has some drawbacks:

  • Natural seawater can contain unwanted parasites
  • Getting seawater from the ocean can be labor-intensive or fuel-intensive and logistically difficult

2. Purified, Pre-mixed saltwater from a local fish store

Local fish stores usually have sophisticated equipment called RODI filters that purify the water before converting it to saltwater for the reef aquarium. RODI stands for Reverse Osmosis De-Ionization and describes the multi-step process this device goes through to purify water. RODI essentially filters tap water to make it pure water before adding the salt. The advantage of buying saltwater from a local fish shop is that you don’t need to:

  • Buy expensive equipment like a RODI filter to produce water
  • Carry out all maintenance work on the device
  • Spend time mixing the saltwater

However, purchasing saltwater from your local fish shop can be expensive, especially for aquarium enthusiasts with a fairly large reef tank.

3. Mixing salt with tap water

The most common method of preparing salt water is to combine a carefully measured amount of the salt mixture (as stated above) with tap water (possibly pre-purified water).

Steps to Making Your Own Saltwater

1: Purchase a standard reef aquarium salt mix

There are several brands of salt to choose from at the local fish shop. If you’re not sure which blend is best for your needs, we recommend that you read my product review on reef salt blends.

2. Put on gloves and follow the manufacturer’s instructions

Most salt mixes require about half a cup of barrier salt per liter of fresh water. Then use a measuring cup to accurately measure the salt. Gloves protect your hands. The salt is very fine and will irritate the skin if rubbed on it. Manufacturers tend to give advice on the bright side.

Collect half a cup (unless otherwise noted on the package) in a reef-safe, chemical-free bucket used only for mixing saltwater or making water changes. If you don’t already have gloves, check out this review of some popular and affordable aquarium gloves.

3: De-chlorinated tap water (1 gallon for every 1/2 cup of salt mixture measured).

Add the appropriate amount of water to that bucket based on how much salt you have measured and how much saltwater you need to make.

4: Aerate the saltwater

Use a small air pump and overhead line to aerate the water. Mixing salt in freshwater causes a chemical reaction and it takes some time for chemical properties such as pH to stabilize. The oxygen, carbon dioxide, and pH values ​​can be adjusted by briefly aerating the water.

5: Measure the specific gravity (density) with a hydrometer or a refractometer

Before adding the saltwater to your tank, measure the specific gravity of the water with a hydrometer to make sure the water contains the right amount of salt.

More often than not, our goal as aquarium owners is to restore a natural reef environment. Natural seawater has a specific gravity of 1.025. For this reason, it is important to read the manufacturer’s instructions and measure what you have created.

6: Record your specific gravity and your water changes

It is never too early to get used to carefully recording test results and observations. Such a scientific approach will help you develop good habits and correct mistakes in case of problems. A great tool to use is a

Marine Aquarium Equipment

Start with the largest aquarium and the best equipment you can afford. Nano tanks don’t cost as much and take up less space, but larger aquariums are more stable and more forgiving of beginner mistakes.

Don’t skimp on your gear! Good quality equipment will perform as advertised and last over time, which your pet fishes are sure to appreciate. Make sure you understand the features and limitations of each device before making a purchase.

Maintaining your coral reef ecosystem

  • Regularly monitor and test water parameters to ensure a healthy marine environment.
  • Change the water 25% at least once a month and perform regular filter maintenance.
  • Feed small amounts of thawed frozen food twice a day. The fish should be able to finish the given portion of frozen food within a few minutes.
  • For a balanced diet, feed your fish a variety of foods, such as Mysis shrimp, ocean plankton, mega seaweed, TetraMarine granules, and sea vegetables. Provide phytoplankton and other invertebrates that feed filters every two weeks.

For healthy corals, add the following reef additives according to the recommended directions:

  • Iodine
  • Buffer
  • Calcium
  • Molybdenum

By following these steps, you will have a complete and successful reef aquarium. Sit back and watch in awe as your aquarium comes to life. Every day there is something new to discover and an infinite variety of changes to witness. Keep in mind that reef aquariums take a long time to establish. Within a year, you will have a beautiful and thriving ecosystem.

Best water balance in your saltwater aquarium

To make good quality aquarium water, it is recommended to use tap water. The safest option is to opt for unsoftened water while you’re at it. So make sure you drain the water before it goes through the water softener. Rainwater is definitely not suitable for a saltwater tank.

After replacing the filter in your aquarium, you will need to rinse it with fresh water for a few hours. Do not reuse this rinse water. In addition, it is important that the new filter has time to become coated with bacteria that break down the ammonia in the secretions. So don’t overload a newly started filter with too many tank residents. The filter reaches full operational capacity only after 21 days.

Saltwater Aquarium maintenance


saltwater tank

1. Water change

Regular water changes are essential for maintaining an aquarium. Volume and frequency vary for each tank, but nearly every refrigerated container changes its water in its aquarium regularly.

Water changes are a method of removing excess nutrients and replenishing the elements. A good basis for starting water changes is to change 20 percent of the water volume every week.

2. Protein skimmer cleaning

Protein skimmers are most likely the dirtiest equipment in your aquarium, and you probably need to pay close attention to them to keep them clean and work effectively.

Depending on the size and biological load, cleaning the drip cup three times a week is a must to keep your aquarium clean and fragrant. If the water is clean enough, you may only need to clean the cup once or twice a week. However, if you are using a large biological load or have a heavy power supply, it may need to be cleaned daily.

3. Cleaning the aquarium glass

We all want to maintain the clarity of our acrylic or glass aquarium. While it can be tricky at times, especially with an acrylic container, with the right tools, your aquarium will be free of algae and scratches.

You should purchase a magnetic scraper for routine cleaning. You can clean most algae with a magnet. If you have an acrylic aquarium, be sure to use an acrylic-safe magnet.

4. Toping up with fresh water

When the water evaporates from your saltwater aquarium, only the freshwater evaporates and the salt remains. To maintain constant salinity, we need to fill our tanks with fresh water.

There are two ways to fill the tank:

  1. Manually
  2. Automatically

For manual refills, simply add reverse osmosis deionized water to the tank, while automatic refills require a freshwater tank and automatic refilling. There are several types of automatic refill systems, but they are all designed to fill the tank with freshwater.

Common Myths of Saltwater Aquarium

  1. It is often said that beginners shouldn’t start with a saltwater aquarium. Marine fish are more sensitive to water quality, so there are fewer errors. However, this shouldn’t discourage beginners. It’s about designing the right saltwater tank. Starting a fish-only aquarium is the simplest option.
  2. Some people say that it is not possible to convert a saltwater aquarium into a freshwater aquarium. In fact, you can do that if you make some changes. You have to empty the aquarium and clean everything with chlorine-free water. All salt must be removed before filling the tank with freshwater.

Recommended Reading: Can Goldfish Live in a Bowl with a Plant?

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