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Salinity in Reef Tanks: How to Keep It Stable (ATO Guide) |…

Evaporation raises salinity every day. An ATO fixes it automatically. Here's how salinity works, what to target, and the best ATO for your tank.

This educational article covers the underlying biology, chemistry, or husbandry concept so you can make better decisions about your own tank instead of just following a recipe. Reefara's learn library is organized by topic: cycling, water chemistry, lighting and PAR, flow patterns, filtration, fish health, coral care, and advanced techniques.

Each article links to related troubleshooting guides, species profiles where the concept matters most, and the calculators that turn theory into a usable number for your tank. If you are new to the hobby, start with the beginner's path; if you are diagnosing a specific problem, the troubleshooting hub will get you to a fix faster.

For hands-on tools, see the reef tools library, including heater sizing, salinity conversion, dosing calculators, and a stocking guide.