Saltwater Science at the National Aquarium
Published December 09, 2013
Just add salt? Not quite. Here's the inside story on how we get our water just right:
As vibrant fish residents swim gracefully in their aquatic habitats at the National Aquarium, the most important element of their exhibit homes - the water - often goes unnoticed.
In total, more than 2 million gallons of water are perpetually pumped, filtered and re-pumped within the Aquarium's nearly 200 water systems. For perspective, the average bathtub holds 50 gallons of water, making the National Aquarium's water content roughly equal to 40,000 bathtubs!
Maintaining the quality of these millions of gallons of water is essential for healthy animals, and it is through the tireless work of dedicated aquarists and laboratory and life-support staff that we can provide the highest quality of water to the thousands of marine animals that call the Aquarium home.
Testing the Water
In every high school across the country, chemistry teachers illustrate water's elemental simplicity by connection to Hs to one O. Sustaining life at the Aquarium, however, as in the oceans, is infinitely more complex. Salinity (the amount of salt), dissolved oxygen (the "air" fish absorb through their gills) and nitrates (waste product) all affect water chemistry.
That chemical balance, in turn, affects those plans and animals on exhibit, as well as fungi and bacteria that cannot be seen with the naked eye. Presenting a healthy environment by maintaining the absolute best water quality for each and every exhibit and backup tank requires a well-coordinated effort between staff across departments.
Each morning, aquarists, under the guidance of water quality expert Kim Gaeta, extract samples from select exhibit spaces. Those samples are then labeled and deliver to the lab, where they are test for ammonia, nitrite and salinity, as well as pH and alkalinity. If there's a noticeable imbalance, staff, under the watchful eye of Laboratory Services Department supervisor Jill Arnold, diagnose the problem and prescribe a solution.
The Right Water
Nearly all of the water in our exhibits is homemade seawater. The National Aquarium, like most Aquariums, manufactures its own. The millions of gallons circulating through the exhibits are a combination of Baltimore City water and a house blend of salts.
Consequently, these salt solutions affect the pH, dissolved oxygen levels and hardness of the seawater, based on their own specific chemistry. Tons of salt is shipped to the Aquarium every year to be used in the manufacturing process. At a cost of about 7 cents per gallon, we spend roughly $150,000 every year to manufacture seawater.
"The Aquarium utilizes a variety of food-grade salts to prepare artificial seawater, using our proprietary formulation developed by our chemist," says Arnold. "Our goal is to mimic natural ocean waters as closely as possible," guaranteeing all of our animals a healthy place to call home!
Our hand-crafted saltwater is just one of the many things we do everyday to give our animals the best quality of care possible. Here's how YOU can support our efforts this holiday season!