What type of Refractometer do I buy?

[Siapin]

I know there are different types of refractometers. I want to buy one.

What are the differences, pros/cons of each type...should I buy battery powered, or light powered? Why are some $30, others $80, and some others $100? Don't they all do the same thing? What's the difference?

 

[Randy Holmes-Farley]

I don't use refractometers, and I do not have a particular brand preference. Whatever type you get, I'd make sure it has ATC (automatic temperature correction), that it is meant for seawater (definitely not a clinical refractometer), and that you check it at least once against a known salinity standard that is not just DI water.

This thread and article may help:


http://reefcentral.com/forums/showthread.php?s=&threadid=741826

Reef Aquarium Salinity: Homemade Calibration Standards
http://reefkeeping.com/issues/2004-06/rhf/index.htm

 

[Siapin]

You don't use refractometers? What do you use? Do you use a probe? Right now, I'm using one of those cheap floating swivel wannabe refractometers. I think it works fine, but I want to be sure of my salinity if I'm going to start keeping sps.

 

[Randy Holmes-Farley]

i use a conductivity meter to measure salinity.

While the Pinpoint is not the brand that I use (I use a lab instrument), it works similarly:

http://www.americanmarineusa.com/salinityfacts.html

You can also make a DIY standard to check your hydrometer as detailed in the article in my first post.