Hydrometer issues

So i got a hydrometer, and "seasoned the needle" (let it soak in salty water for 24 hours) and got a good reading the first time i used it after that. (Picture included) I was at a sg of 1.015. Now 3 days later i went to check with my hydrometer, and the needle won't float at all.

Is it my hydrometer, or can salt dissipate within 3 days?

 

cupid of crime, it may be faulty or

you need to clean them in freshwater between testing otherwise if you just empty them and leave them around, the water on them evaporates leaving salt crust, which makes the needle heavier and then cant float

soak it for a while and then re test
Steve

 

those thing suck.....invest in a refractometer on ebay for 27.00 bucks maybe cheeper...look at the ATC ones they are good for the money and work well

 

Make sure you get all the bubbles off of the needle. Even one microbubble can make the reading faulty

 

I would reccomend a refractometer as well you will never get an accurate reading with that.

 

2nd on the refractometer! Trust me its night and day difference.

 

+1 Swing arm hydrometers are notorious for being inaccurate, if you would like to continue using it at least check it against a calibrated refractometer at an LFS or someone in a local reef club or something.

They're 1000% worth the investment though, and really aren't that expensive.
Refractometer for reading salinity w/ Free Calibration fluid - English

 

all great advice and totally agreed with for anyone with a reef set up

but bear in mind cupid of crime has a 10 gallon brackish tank with
3 mollies (2 silver, 1 Black), 3 little tiny mollies (born 2 days ago

Im pretty sure a swing arm if cleaned thoroughly between usages
will be suitable for present purposes

Steve

 

Thanks again all for the great advice! i think i will soak with FW for 24 hours then retry.
OH BTW I think my eel has finally eaten. 3 ghost shrimp put in yesterday, 1 left today. Here's hoping!!!!