Originally posted by Shnabbles
lol i have no idea what happend....
If i get a refractometer, would i still need a hydrometer or do they do the same thing?
A refractometer measures how much the water bends light (refractive index.)
A hydrometer measures how much the water weighs (specific gravity.)
Neither measurement is useful by itself, for saltwater aquarium purposes, both get converted into salinity. Refractometers are generally recingized as being more accurate measures of salinity than hydrometers. You only need one, unless you want the hydrometer on the side for a wine making operation.