Q. What salt level should I maintain?

A. In the ocean the specific gravity ranges from 1.022 to 1.030, on average the specific gravity of the ocean is 1.026. In typical aquariums the specific gravity ranges from 1.020 to 1.025. There are many advantages to keeping a lower specific gravity in one’s aquarium. Specific gravity increases as water evaporates because the dissolved salts remain in the water as the water level decreases, therefore if the specific gravity is initially low, evaporation is safer and there is less of a chance of the specific gravity jumping up to dangerous levels. Lower specific gravity also means more dissolved oxygen, reduced stress, reduced number of parasites and reduced energy requirements for your animals. When keeping an aquarium with low specific gravity one must be sure to take caution and acclimate new animals slowly to avoid shock. It may be difficult to keep organisms from the red sea in lower specific gravity because they may be more stenohaline (less tolerant of specific gravity changes). Over all an ideal specific gravity is around 1.023, not too low for acclimation and allows for comfortable evaporation margin.