Can a Hydrometer go bad?

[matt52]

I have an Instant Ocean hydrometer and recently the readings have been really wierd. At the begining of the week the water read 1.024sp and two days later it jumped to 1.028 but I know that it couldn't have jumped up that quickly.:notsure:
Thanks for any help

 

[woodymdt]

I've read that a few things can cause misreadings on hydrometers. There could be some salt caked on the needle, which could cause incorrect readings. Also I read if there are any air pockets in the chamber, that could make your readings off as well.
:jumping:

 

[bang guy]

How often do you top off your tank?

 

[matt52]

I top of my tank weekly

 

[bang guy]

If you have a high evap rate your S.G. could have jumped by that much. You might want to consider topping off daily. Typically the plastic hydrometers are fairly inaccurate.

 

[dedwards]

Also be sure to top off with freshwater...water evaporates and leaves salt behind

 

[lion_crazz]

Yes, they can definitely go bad too, however. I have dealt directly with a lot of the manufacterers who make hydrometers and some say that they should be replaced every 6 months. In two years of replacing hydrometers every 6 months, you could have had a refractometer!
In your case though, it just sounds like you lost a lot of water to evaporation.

 

[ophiura]

Also be sure to rinse your hydrometer with fresh water and soak it every so often in some white vinegar to remove any buildup. But I agree, if you are only topping off once a week, it could easily jump pretty high.

 

[mbrands]

Do you leave your hydrometer in the tank? If you remove it, the tiniest of air bubbles could throw the reading off by that much.