New Toy for Xmas!

Google's blogger has been acting up lately so i've been slow with the updates. Anyway I've gotten myself a new toy for xmas! and its a refractometer! Thanks to bro Honda from the reef club, passed it to me at great price.



So here it is! What does it do? it gives a very accurate reading of the aquarium water's salinity (the amount of salt inside the water). In a previous post, I discussed about the hydrometer, how it worked and how it measured salinity. a hyrdometer is a useful device to have but it will only give (i prefer to use this term) an indication of salinity. Its accuracy can be easily affected by bubbles stuck on the swinging measurement arm or salt crystals forming on the device itself because you don't clean it well after use. Besides that, the principle its built upon has an intrinsicly large margin of error.

How does a refractometer work? Its basically an optical instrument with a prism being the basis of its physics. You drop some aquarium water onto the prism, hold it up against the light and you peer down the device. I believe that because water with different salinity levels have different refractive indices, the refracted light is directed onto a scale to give a correseponding reading. Pretty complex? ha! I think it's pretty cool!

My hydrometer indicated the water's specific gravity was 1.021, the refractometer gave a reading of 1.025. Grossly over the acceptable range of 1.020-1.023. Diluted the water and dang calcium and magnesium levels plunged.