Salinity checker

[Poseidons Reef]

Have been using Hanna salinity checker a calibrate once a month. Did some research and heard positive comments about Tropic Marin Hydrometer being the most accurate way to test. Hanna will read 1025 and Hydrometer reads 1026. What is your opinion about hydrometers?

 

[KStatefan]

That is what I use. My Hanna always reads lower than the hydrometer also.

 

[Poseidons Reef]

That is what I use. My Hanna always reads lower than the hydrometer also.

Yes mine too. Thank You

 

[Randy Holmes-Farley Verified Community Expert]

Have been using Hanna salinity checker a calibrate once a month. Did some research and heard positive comments about Tropic Marin Hydrometer being the most accurate way to test. Hanna will read 1025 and Hydrometer reads 1026. What is your opinion about hydrometers?

I do not agree at all, and think it is clearly not true that the TM hydrometer is the "most accurate" method for measuring salinity, but it is certainly a fine way to go, at least if the accuracy is confirmed once. It has the advantage that unlike many devices, it cannot be calibrated so cannot be accidentally miscalibrated.

There's no need for a device to be the "most accurate" to be among the best choices for reefers.

I prefer to use a decent conductivity meter which I check each time against a standard. It is far more convenient to use in many situations than is a large glass hydrometer of any type.

 

[Poseidons Reef]

Have been using Hanna salinity checker a calibrate once a month. Did some research and heard positive comments about Tropic Marin Hydrometer being the most accurate way to test. Hanna will read 1025 and Hydrometer reads 1026. What is your opinion about hydrometers?

I agree. Thank You

 

[reefmaster70]

you all DO know there are "other" glass hydrometers on the market that work exceedingly well for our purposes. As a long time wine and mead maker, i use a glass hydrometer in a graduated cylinder all the time to watch a fermentation as it progresses. This is basically the measure of the density of water with sugar (or lack of) in it. What's in the water, however, is irrelevant. It can just as easily be salt as well. You can pick up a very accurate glass hydrometer these days for under $20. You don't have to spend over $40 on the T.M. one. Here's a pic of the one I use, that has both a thermometer on it, and the S.G. scale. That way you can easily do the calculation/temp correction (if need be) to get your accurate SG reading for your saltwater. It really is THAT simple.

 

[Lagoon Reef Keeper]

Glass hydrometer is objectively much more accurate than any digital device. (Assuming youre correcting for temp if your tank is different than the hydrometers calibrated for, usually 77-78 depending on manufacturer) I’d rather use a glass hydrometer or a calibrated refractometer before I ever touch digital (which I never use)

 

[Randy Holmes-Farley Verified Community Expert]

Glass hydrometer is objectively much more accurate than any digital device. (

Such a broad statement, is, of course, inaccurate. The simple fact that the modern seawater salinity scale (PSU) is defined based on conductivity should make that clear.

 

[Lagoon Reef Keeper]

Glass hydrometer is objectively much more accurate than any digital device. (

Such a broad statement, is, of course, inaccurate. The simple fact that the modern seawater salinity scale (PSU) is defined based on conductivity should make that clear.

No sure I understand what you’re getting at.

 

[Lagoon Reef Keeper]

Glass hydrometer is objectively much more accurate than any digital device. (

Such a broad statement, is, of course, inaccurate. The simple fact that the modern seawater salinity scale (PSU) is defined based on conductivity should make that clear.

If you have a crap at home digital salinity the store that beats a glass hydrometer feel free to share. don’t think anyone is doing conductivity tests, least not someone asking the question originally asked.

 

[davidm777]

I prefer to use a decent conductivity meter which I check each time against a standard.

Comes as a surprise you prefer a conductivity meter. Although checking with a standard is always the way to go with a calibratable measurement device.
I ended up settling on a Milwaukee refractrometer when I went down this rabbithole. Is my understanding conductivity meters will accumulate buildup over time making them unreliable.

 

[bushdoc]

I am also using Tropic Marin Hydrometer and manual refractometer.

 

[Sneak]

I just purchased a Tropic Marin Hydrometer specifically to test against my Hanna Salinity Checker.

After freshly calibrating the Hanna at 77 degrees fahrenheit, it was still reading 1.024 against the Tropic Marin Hydrometers 1.026. I cant believe I went this long without a Hydrometer.

Knowing that the Tropic Marin is always going to be accurate at 77 degrees water temp without having to calibrate it is a great benefit. Even after calibrating my Hanna Checker, it did not read as accurate as the hydrometer. It also helps that I keep my tank at 77 degrees, which makes measuring easier for me.

 

[Randy Holmes-Farley Verified Community Expert]

If you have a crap at home digital salinity the store that beats a glass hydrometer feel free to share. don’t think anyone is doing conductivity tests, least not someone asking the question originally asked.

Huh? Lots of people use conductivity meters for their reef tanks at home, including many regulars in this forum, and like hydrometers, they range from bad ones to great ones. I have used high end conductivity meters for decades to measure both tank water salinity and kalkwasser potency.

I agree with you that a good hydrometer beats a crap salinity meter.

But a good conductivity meter definitely beats a crap hydrometer, and may well beat any commercial hydrometer.

The modern salinity scale is BASED on 35 PSU equals the conductivity of a solution made from KCl and water (KCl mass fraction of 32.4356 g kg−1). One primary reason to base the scale on conductivity and not density (hydrometer) is that it provides a consistently accurate way to measure salinity against a standard.

 

[Randy Holmes-Farley Verified Community Expert]

Comes as a surprise you prefer a conductivity meter. Although checking with a standard is always the way to go with a calibratable measurement device.
I ended up settling on a Milwaukee refractrometer when I went down this rabbithole. Is my understanding conductivity meters will accumulate buildup over time making them unreliable.

It should not be be a surprise since I have been posting about it frequently for 30 years. Many of us at Reef2Reef, as well as many companies that analyze seawater commercially (including icp companies such as Oceamo) measure salinity by conductivity because it is easily calibrated, verified, highly precise, and accurate.

To your point about contamination of the electrodes, it is a concern with any device measuring salinity to leave them in reef tanks 24/7, and I do not generally recommend doing so, whether it is a hydrometer or a conductivity meter.

 

[Randy Holmes-Farley Verified Community Expert]

I just purchased a Tropic Marin Hydrometer specifically to test against my Hanna Salinity Checker.

After freshly calibrating the Hanna at 77 degrees fahrenheit, it was still reading 1.024 against the Tropic Marin Hydrometers 1.026. I cant believe I went this long without a Hydrometer.

Knowing that the Tropic Marin is always going to be accurate at 77 degrees water temp without having to calibrate it is a great benefit. Even after calibrating my Hanna Checker, it did not read as accurate as the hydrometer. It also helps that I keep my tank at 77 degrees, which makes measuring easier for me.

Do you know the know the hydrometer is accurate?

I'm not saying it isn't, but you assume it is when it might not be.

What did you calibrate the Hanna with? I have a concern that its calibration fluid may be the thing that makes folks frequently find it reads low, not the device itself.

 

[reefmaster70]

Do you know the know the hydrometer is accurate?

I'm not saying it isn't, but you assume it is when it might not be.

What did you calibrate the Hanna with? I have a concern that its calibration fluid may be the thing that makes folks frequently find it reads low, not the device itself.

Randy...what are your thoughts/opinions on the Pinpoint ATC conductivity monitor? I have one, and have just never put much faith into digital units. Like I said, as a long time "wine maker". I've always relied on the glass hydrometer. With my reef tank, I've always used an ATC refractometer, and check the calibration every few months. I've never really even thought about using my glass hydrometer's until the last year or so. I just don't know if I should start using the Pinpoint for daily monitoring, and just keep double checking it with a glass hydro. or not waste my time.

 

[miller75]

If you have a crap at home digital salinity the store that beats a glass hydrometer feel free to share. don’t think anyone is doing conductivity tests, least not someone asking the question originally asked.

The Hanna salinity checker is a conductivity test isnt it?

 

[Randy Holmes-Farley Verified Community Expert]

Randy...what are your thoughts/opinions on the Pinpoint ATC conductivity monitor? I have one, and have just never put much faith into digital units. Like I said, as a long time "wine maker". I've always relied on the glass hydrometer. With my reef tank, I've always used an ATC refractometer, and check the calibration every few months. I've never really even thought about using my glass hydrometer's until the last year or so. I just don't know if I should start using the Pinpoint for daily monitoring, and just keep double checking it with a glass hydro. or not waste my time.

This one?
https://americanmarineusa.com/products/pinpoint-salinity-monitor
I had one that I used for many years. It is more than accurate enough for a reef tank, and the main reason I preferred my Orion Model 128 is that the Orion can to temp equilibrium and hence had a stable value much faster than it when I put the probe from my cold basement into warm tank water.

I'd definitely check it in a good standard, and then use it. You can manually adjust the values if the calibration is not close enough.

 

[Randy Holmes-Farley Verified Community Expert]

The Hanna salinity checker is a conductivity test isnt it?

Yes.

Conductivity meters range from very cheap (<$20) to extremely expensive (>$1,000)), hence my initial comment that to criticize all digital salinity meters equally is not accurate.