View Full Version : Calibrating swingarm hydrometer?

01/04/2007, 01:16 AM
Ok, so I know you can't really "calibrate" a swingarm hydrometer, but isn't there an easy way to tell if yours is even close? I read HERE (http://reefkeeping.com/issues/2006-12/rhf/index.php) that you can use a solution of 73.1g iodized salt and 2.0 L of pure water to get a mixture that's pretty much 35 ppt (~1.0264 on a hydrometer) to use to calibrate a refractometer. I figure it will work on a swingarm too. What are your comments/ideas on this?

01/04/2007, 05:18 AM
None come to mind. The swingarm types are all slightly different IMO. If there is a tiny bubble stuck on the swingarm anywhere it will give you a false reading. I use a refractometer & never have any issues. I check it every month so I know it is reliable.

01/04/2007, 07:11 AM
You have to use s.g. calibration standard.

Everthing is in the following article.


Randy Holmes-Farley
01/04/2007, 09:43 AM
That recipe in the first post is only for refractometers, but a similar one, in Bojan's post, will work for a swing arm, and any other type of hydrometer. :)