Salinity measures dissolved salt content in water. Most backyard pond fish (koi, goldfish, tilapia, catfish) are freshwater species with little tolerance for salinity, while some aquaculture operations intentionally work in brackish or full saltwater systems for different species entirely. Adding aquarium salt to a freshwater pond is sometimes used briefly as a treatment, not as an ongoing water parameter to maintain.
Salinity
Lokorio
Certified Aquaculture Expert & Founder, Memeilo Ponds
Moses Lokorio is a certified aquaculture expert with over 6 years of hands-on experience helping fish-pond builders create healthy, balanced pond ecosystems. At Memeilo.com, he writes detailed, data-driven guides to simplify pond construction, maintenance, and fish care for DIYers and professionals alike.