Hydrometers

[tybud]

Quick question about hydrometers
I have a 60 gal fish only tank that I have been using a glass hydrometer that is suspended in the water. I kept it at the appropriate level(1.020-1.023). Then I set up a 20 gal hospital and bought a new hydrometerby aquarium systems. It is the seatest s.g. meter. But the problem is that it read that my s.g. was way high at about 1.030 where my glass hydrometer only showed it being a little high( when I took this measurement) I want to know which one I should trust. I am more inclined to go with the new plastic seatest because it is newer and has been through less moving. Any ideas. Thanks

 

[reeferx]

I seem to recall hearing that the glass ones were better, but my memory is a little foggy on this.
Look for air-bubbles on the needle of your seatest. It may explain your higher reading. Shaking it a little underwater before testing helps to get rid of the bubbles.

 

[fshhub]

the seatest, is it electronic, floating, or one of those that you fill and the needle bobs or floats??
if it is one that you fill and the needle floats, often tiny bubbles or such will make the needle stick, giving a false reading, what we do with ours is we tap teh needle with a piece of plastic, adn the side wall of the container, to make sure there are no more bubbles(and i do mean tiny), this does help alot with consitancy, which may be the problem
HTH

 

[mr . salty]

Adjusting for the temp on the glass one was my first guess,and bubbles on the needle of the new one is my second guess.I have had both and I prefer the plastic one myself.It is easier too read.And you dont have to adjust for water temp...

 

[kdlbem]

If it is a swingarm type, you probably need to season it by filling it with saltwater and letting it sit overnight(if it's new. If it's not, sorry, just thought it was worth mentioning).
HTH,
B