Deep Six Hydrometer

[ArmyGoNow]

I have a question about my Deep Six Hydrometer. I keep getting different readings from my testing. Is this a good hydrometer or is it me and my methods. The temp is pretty steady at 80 degrees but my reading range from 1.018 to 1.030 off the scale. It doesn't seem to have any pattern to it ........ any help out there.

[yanasina]

Are you sure you don't have any air bubbles on the arm? Even littly tiny ones can skew the reading. I just got a deep six after my previous hydrometer took a header off the top of the tank onto the floor and both of them have given false readings because of this. Just tap it on something after it's full to shake those bubbles out.

[budhaboy]

Army,
sent you an e-mail, plus I think I have a "floater" hydrometer for ya also if you want to try a different type. JP.

[Al]

All hydrometers that work with a floating plastic arm can be difficult to use. As yanasina pointed out, there could be tiny bubbles making the arm lighter than it should be. There's also temperature to consider, and after a while you get deposits of minerals on the plastic that throw the readings off. Best thing to do is
a) carefully clean the hydrometer with vinegar
b) rinse thoroughly
c) take a few readings after tapping the hydrometer to get those bubbles off.
Even if you get consistent readings after this, you might want to get another one, and compare the readings against each other, to make sure you are not getting consistently wrong readings.
An even better thing to do is to get a refractometer or one of those battery powered salinometers - they are pricier (not too costly mail order) but a lot more accurate and easier to use, and last forever compared to hydrometers.

[ReefDream]

My SeaTest hydrometer that is about 10 years old measures my water .001 lower than my Tropic Marine Hydrometer. Now that I know this, I don't bother with the hydrometer but keep delta in mind.