Salinity

[jbfastlane]

I have a maybe dumb question. I originally purchased a cheap plastic square box type with the plastic arrow hydrometer. I've been using it faithfully - however I found a glass one on sale with the temp inside as well as the salinity and decided to buy it as I've been told the cheap model isn't very accurate.
Well the plastic box says I have 1.025 and the glass floater says more like 1.018 -- now I'm worried. Which do I trust. My water temp is around 77-78.
Anyone have advice on these things?

 

[flamingkingofhe]

ive been using the plastic box for two years never had any problems my opinion box

 

[jbfastlane]

My worry is that they vary so much. Which is right? Or I guess which is closer to right?

 

[bang guy]

Floating glass hydrometers are normally much more accurate than the swing-arm type. Be sure you're reading it at the true water level.