Hyrometer Error?

[flapjack1439]

I have an Instant Ocean Hydrometer that's about 18 months old. I'm getting a reading of 1.020 on the water from my lfs. Do these go bad after a while?

 

[Pufferpunk]

I prefer a refractometer, myself. Hydrometers can be off by as much as + or - .005. At least compare it to the readings of a refractometer, so you know if it's off & by how much.

 

[Brooklyn8]

My lfs sells salt water at 1.020. It right between a reef salinity and a fish only salinity.

 

[yupyup]

Re: Hyrometer Error?

<a href=showthread.php?s=&postid=7710167#post7710167 target=_blank>Originally posted</a> by flapjack1439
I have an Instant Ocean Hydrometer that's about 18 months old. I'm getting a reading of 1.020 on the water from my lfs. Do these go bad after a while?

make sure you compare that reading with a refrac. i had an instant ocean last year and it was off by .004. Most lfs carries refrac. so you can bring it to them for comparison.

 

[PSam]

I got salt from LFS at 1.016 once, it's usually about 1.021, which is still low. Kind of makes me salty <!> that I have to add to purchased water, but I keep my reef on the high end.

I also use the same hydrometer, which is usually not far off from refractometer. Make sure to clean it well with HOT water then rinse with cold, get all the deposits out. I think refrac still the best way to go for accuracy though.

 

[blackdak]

Those swingarm hydrometers can be very accurate. To say that the refractometer is better is not entirely true. The biggest problem, which affects both the hydrometers and refractometers, is the calibration. A refractometer that isnt calibrated properly is just as bad as a hydrometer that isnt calibrated. Refractometers can become out of calibration pretty easily, thus requiring periodic calibration.

Even as a sucker for neat gadgets, IMO a $10 hydrometer that works well doesnt justify the additional cost of the refractometers.

 

[MBasile]

lfs often keep salinity low to keep down pathogens and also to save a little on the salt.

coming from a former lfs employee, but it was not a good lfs by any extent which had to do with why i quit.