In the early days of keeping a marine or saltwater aquarium you had to go to the ocean to get water. Now, years later, questions arise; where do you get the salt to make saltwater for the fish? Do you just add a salt mix to water? If so how do I know if I mixed the salt correctly? Then you hear rumors that keeping the saltwater level in your aquarium is difficult. Let us look into the world of salt for creating a healthy environment where fish will thrive.

Rest assured that you no longer have to drive to the ocean to get saltwater. You can go to most pet and aquarium stores and purchase salt for your aquarium in either a dry salt mix form or premixed ready to use water. There are four different ways to purchase saltwater for your aquarium.

The most popular is to purchase dry, premixed salt in a box, plastic bag or bucket. Just follow the directions on the label and add the recommended amount of salt to tap, RO, DI or distilled water.

Another popular way to purchase salt for your aquarium is to buy premixed saltwater. Many pet and aquarium stores mix large quantities of saltwater in vats so that consumers (you) can purchase it by bringing containers (usually holding 5 gallons) to fill. Most stores use purified water such as reverse osmosis or de-ionized water to mix with the sea salt mix. Purified water removes many unwanted pollutants from the water.

One of the newest methods is to buy bottled saltwater. This water is collected from the ocean, purified and bottled. This water is more expensive than dry salt mixes but the manufacturers claim many benefits from using their water.

The final and most exciting way to get saltwater is to move near an ocean and go off shore to collect all the water you need.

Most of us will go to our local pet and aquarium store to purchase saltwater for our aquariums. Whichever form of saltwater you choose before you add any saltwater to your aquarium always test it.

The first test should be to measure the specific gravity or amount of salt in the water. You want to ensure the salt content is correct; specific gravity should be between 1.019 and 1.025. Test the specific gravity with a hydrometer. One popular hydrometer style is a plastic box with a floating swing-arm. As you fill the plastic box with saltwater the swing-arm floats and points to a scale which tells you how much salt is in the water. If you are reading too high on the scale add more water, if too low add more salt mix. Hydrometers are easy to use and they make testing saltwater a breeze.

Once the salt level is correct ensure your pH, ammonia and nitrite levels are also where they should be. One final thought: salt never evaporates, so anytime the water in your aquarium drops due to evaporation, add plain water (without salt added) to fill your aquarium back up.