Ok so in my nano I have a pump pumping water into a refgium and than it over flows back into the tank. The pump failed and the refugium had a salinity of 1.036 by the time I noticed. I keep a zebra hermit in it to both survived and don’t seem stressed. The crab is there to help prevent algae from clogging my baffles. I guess these little guys are nearly indestructible to errors.