hydrometer?

[e-cat]

what type of hydrometer has a better accuracy the glass tube or the plastic ones with the moving dial?

 

[reefrunner69]

A quality floating glass hydrometer of 12" in length or more is much more accurate that the swing arm hydrometers. If your LFS has a refractometer (or you know someone that does) you can check your swing arm against that and then compensate for any differences.

 

[e-cat]

my lfa has a floating glass one that is 12" so ill pick that one up.