Measuring Salinity

[eruss]

Cheers Anthony, hope all is well.

I would like to hear your opinion on some of the different methods (devices) available for measuring salinity/SG.

I've gotten by for nearly three decades using glass floating and plastic swing-arm hydrometers, but I'm leaning toward moving on to either a refractometer or electronic salinity monitor (e.g. - Pinpoint).

I'm aware of your viewpoint on "hobby handheld vs benchmount laboratory" equipment, but that aside, how do you rate/compare the available hobbyist refractometers and electronic salinity monitors?

And if you favor the refractometer, do you have a preference/recommendation on model?

Regards,

[Anthony Calfo]

believe it or not... I feel very strongly that the very best means for measuring SG is a quality glass hydrometer. Even the cheapo ones if inaccurate are still precise. That is to say, even if the scale inside the glass tube was set miscalibrated, the unit still will read precise (off by the same amount all the time) about indefinitely.

And for $30 or so... you can get a very high quality lab grade glass SG unit.

Plastic hydrometers are only worth about as far as you can throw them IMO. Most brands still have a problem where out of the pack ten in a row will not give ten same readings. And they are easily jarred to misread. Inconsistent over time by far.

Now pitting the cheapo handheld refractometers up against a high quality glass tube hydrometer... glass again. Hands down over time. They simply do not corrupt easily. A glass hydromter is either working perfectly or its smashed... there's no in between :D But the cheap refractometers largely fall in the category of "good things are seldom cheap and cheap things are seldom good". You would be staggered to know how little they cost on import to the US. No really... its staggering

That said... if I wanted to invest in something that was very accurate and also not too fragile/tedious to use - I'd buy a quality handheld refractometer. A lab grade one though... its gonna cost you a couple hundred to get it. And yes.. a bench top refractometer is generally much more reliable.

OK... now for the practical advice for the average aquarist: use the cheap plastic hydrometers because they are quick and durable... but always check against a glass hydrometer every couple of months to verify accuracy. This is an affordable and accurate solution instead of buying expensive equipment.

best regards :)

Anthony