Can I just add regular table salt to a marine aquarium or must it be a specific formula designed for saltwater aquaria?
Salinity is not the same thing as specific gravity. In fact salinity does not even apply when measuring “salts” in an aquarium so is truly useless except to measure the concentration of ions in the water. What you measure when you take a reading with your hydrometer is the density of the water, which increases as you add more OCEAN salt. Table salt (sodioum chloride) is only one salt found in the ocean, and actually forms only a very small percentage of the total salts found in commercial aquarium mixtures. The major salts are potassium salts (also called bitter salts) such as potassium chloride, potassium iodide, etc. Epsom salt is an example of a bitter salt, but you can’t use that alone either. Bottom Line No, you cannot substitute table salt or any single salt for a commercial mix, because you would throw off the ratio of these naturally-occuring salts and that will eventually kill your fish. Top • How do I mantain a saltwater fsh tank with mostly tropical fish? You need to get a b
