Salinity

Kryorke · Post by **Kryorke** » Tue Mar 25, 2014 3:01 pm

Does anyone know what the salinity of hermit crabs saltwater should be? I have always followed the directions on the box to a T; today I bought a hygrometer(hydrometer?) that suggested the saltwater should measure 1.020-1.026. Mine was crazy high off the chart, and I had to add A LOT of fresh water to bring it down into the recommended range. Since I followed the directions on the Instant Ocean package, I'm at a loss. Should I go by hydrometer or IO package? Thx!!!!

Crabber85 · Post by **Crabber85** » Tue Mar 25, 2014 7:34 pm

@Kryorke, Hermitcrabs can regulate the salinity of the water by drinking fresh water or pumping it into their shell which then gets mixed on an ostopic level until it is the perfect level both in the shell and in their bodies.This is why its not necessary for us to regulate the slainity of the salt water as it is rendered moot by the crabs.8 table spoons or 1/2 cup of IO salt to 1 gallon of dechlorinated water will yeild full strength sea water so the directions on the box are sound.

Post by **JediMasterThrash** » Wed Mar 26, 2014 3:18 pm

Hygrometers measure specific gravity, not salinity. The specific gravity of sea water is around 1.025 (1.023-1.026), though different oceans can vary from 1.022 to 1.035.Brackish would be around 1.005 to 1.025That said, Crabber85 is right, I usually make my saltwater a little extra potent just to contrast with the freshwater and make sure the crabs have the ability to regulate it to however they want.Also, since the water evaporates but not the salt and you keep adding sea water, the sea water continues to increase in salinity over time.