Better to buy a good one

Hi ,
I have been having some problems with my inverts , I finally checked my hydrometer at work and found a huge problem with the one I have been using at home.
Its one a couple months old and its junk..

it was reading 1.025 numerous checks and rinses on my tank.
I took a sample to work and checked it on rather expensive one and it reads
1.016.... thats just bad... fish seem to tolerate that lower spec gravs but the inverts just die.

doug

 

Doug,

I'm sorry this happened to you.


With that said, I don't consider that hydrometer junk. Swinging float-arm hydrometers are amazingly accurate considering they are basically a piece of plastic.

Here's my recommendations whenever buying a float-arm. Before you leave the store, use it in the stores tank to make sure there's no problem with it. These instruments are highly sensitive to drops. The unit you purchased could have been dropped during shipment or even while at the LFS. Even if it's good from the LFS, if you accidentally drop it, you need to make sure it's still calibrated correctly again.

Beyond the dropping issue, there's the issue of built up salt giving false high readings. They MUST be rinsed after every use with fresh water. This is preferably RO/DI water because even tap water has dissolved salts in it. However, tap water is better than allowing saltwater to dry in it.

Periodically, soak them in white vinegar and then rinse them out with fresh water.

 

dUH

hi,
Should have thought of the Vinegar, Oh well will try it maybe we can save this one, I just can't believe how easily they can change, The LPS told me to bring it in once a month or so and they will check it. They checked it and said it was right on the money when I first bought it , so I guess maybe it has some lime/salt build up, I was checking things almost daily i woud rinse it well and invert it to dry. I wonder if the inverting messed up the arm....hum?????
I will have the more stable Meter the 28 of this month and I will keep it in the case.
It does work better after soaking to R/O water over night will try the vinegar..
Doug
I guess the only reason I posted is to remind other newbies those things can go bad or change almost over night.
and the crabs and shrimp seem to cringe any time anything is a little off if you change the spec grav more than .01 they seem to go into shock.
Yikes.

psps I had a problem moving the fish from the smaller to the large 55 gallon, I thought I caught everyone and changed the water, I did turn the smaller 30 gal into a braquish african tank with a spec grav of 1.003.
Any who It was late I was tired I refilled the 30 with some old saltwater ( save old sea water for african tanks it really improve their color and I am recycling the salt,cheap cheap. Braquish systems handle waste a lot better than saltwater system.) and mosty well water, its was around 1.003 a little cool about 68 deg so I went to bed thinking I'll let it warm up and settle over night this allows the iron to settle in the well water. The next morning I powered up all the lights on all of the tanks And I noticed a young peach damsel was swimming about in the 30 braquish tank he didn't look to good. but he was moving about.
I tried to gradually acclimate him back to the saltwater tank and he seemed ok.
After a couple days he was fine, man those saltwater fish are tough.. I stil have that little guy he's swimming about..

 

Temperature also plays a big part in the readings of salinity!!

 

That's true if you are using a floating glass hydrometer that is calibrated at a different temperature than the tank water is at.
However, the plastic swing arms have virtually no error due to temperature differences in the ranges we normally see in salt water aquariums.