Salinity Please help me make sense of this

[ReefHunter006]

I have three Hanna salinity meters, a hydrometer, and some cheap Amazon salinity tester.

Why does the hydrometer seem so high?

Which of these is right? I can’t make sense of any of them cause nothing seems to line up.

 

[EeyoreIsMySpiritAnimal]

The best thing to do is test with a 35 calibration solution

 

[crazyfishmom]

Do you have any 35 ppt calibration solution on hand?

Given the differentials across the board I would consider trying to look at a standard solution prior to making any changes based on any of these readings.

 

[neonreef3d]

the hydrometer is the most accurate way of testing, just make sure your water temp is at 77F

 

[ReefHunter006]

Do you have any 35 ppt calibration solution on hand?

Given the differentials across the board I would consider trying to look at a standard solution prior to making any changes based on any of these readings.

I tried Randy’s last night.

Hanna’s came in between 28-29ppt.

Inam lookinng my mind trying to figure out what is going on.

All the Hanna salinity temps are different by 2-3c each.

Aside from the hydrometer all of these tests have been calibrated with their supplied solutions. I have been through 5 packets in the last three days.

 

[crazyfishmom]

I tried Randy’s last night.

Hanna’s came in between 28-29ppt.

Inam lookinng my mind trying to figure out what is going on.

All the Hanna salinity temps are different by 2-3c each.

Aside from the hydrometer all of these tests have been calibrated with their supplied solutions. I have been through 5 packets in the last three days.

The Hannah salinity tester and all other meters for that matter have to be calibrated every so often. Sounds like the hydrometer might be right if the Hannah is coming in at 28-29 with the calibration solution.

 

[ReefHunter006]

The Hannah salinity tester and all other meters for that matter have to be calibrated every so often. Sounds like the hydrometer might be right if the Hannah is coming in at 28-29 with the calibration solution.

I calibrate twice a month on all my salinity testers that can be calibrated.

**edited week to month

 

[slogan315]

Throw away the Hannas. Best thing I ever did for my tank.

Edit: Hanna salinity*

 

[ReefHunter006]

Throw away the Hannas. Best thing I ever did for my tank.

Edit: Hanna salinity*

How do I trust the hydrometer with the wide range of temperature across all the pictures though?

Refractometer reads 35ppt.

 

[slogan315]

How do I trust the hydrometer with the wide range of temperature across all the pictures though?

Refractometer reads 35ppt.

I have never used a hydrometer, so can’t comment unfortunately. I use a refractometer calibrated with distilled water before every use. I just had a problem where my salinity was at 1.030 despite calibrating the Hanna. Once I switched to a refractometer and got my salinity under control, magically all my problems in the tank went away.

As for temps with the Hanna, I found it takes a while in the water to get near the actual tank temps, and even then, it was often 0.5 deg low. I believe Hanna salinity checkers adjust the EC salinity reading based on the temp. So if the temp measurement is off, so will the salinity.

 

[crazyfishmom]

How do I trust the hydrometer with the wide range of temperature across all the pictures though?

Refractometer reads 35ppt.

Then stick to the refractometer if that’s the readout that’s calibrating appropriately.

 

[ReefHunter006]

I have never used a hydrometer, so can’t comment unfortunately. I use a refractometer calibrated with distilled water before every use. I just had a problem where my salinity was at 1.030 despite calibrating the Hanna. Once I switched to a refractometer and got my salinity under control, magically all my problems in the tank went away.

As for temps with the Hanna, I found it takes a while in the water to get near the actual tank temps, and even then, it was often 0.5 deg low. I believe Hanna salinity checkers adjust the EC salinity reading based on the temp. So if the temp measurement is off, so will the salinity.

The temps have been stable in those pictures for at least 1-2 minutes prior to the photo being taken.

My issues is I have three of the dang Hanna salinity testers and they all read low and vary in temp by a substantial degree.

 

[ReefHunter006]

Then stick to the refractometer if that’s the readout that’s calibrating appropriately.

i have no reason to believe that one is reading correctly. It’s reading 35ppt for my sample, but the same sample is ~33.4ppt with the precision hydrometer and even worse with the Hanna’s.

Shouldn’t the hydrometer be the most accurate since it doesn’t require calibrating?

 

[ReefHunter006]

Same sample different Hanna’s. All Claire’s day of.

 

[crazyfishmom]

i have no reason to believe that one is reading correctly. It’s reading 35ppt for my sample, but the same sample is ~33.4ppt with the precision hydrometer and even worse with the Hanna’s.

Shouldn’t the hydrometer be the most accurate since it doesn’t require calibrating?

Does your hydrometer read at 1.000 with DI water at the same temp? Just an easy check. Hydrometers can malfunction too.

 

[ReefHunter006]

Does your hydrometer read at 1.000 with DI water at the same temp? Just an easy check. Hydrometers can malfunction too.

I’m not sure how to check that. The stock only goes from 1.02 to 1.03.

 

[crazyfishmom]

I’m not sure how to check that. The stock only goes from 1.02 to 1.03.

You should be able to just use RODI and check that it is at 1.00. At least all the ones I’ve ever seen will let you do that.

 

[ReefHunter006]

That black line at the top is for 1.02. There is no indication of 1.00

 

[homer1475]

Calibrate a refractometer, or the hanna, and throw the rest in the trash. Just use 1 or you'll literally go crazy trying to make them match.

These are hobby grade kits, not scientific grade kits, they all have a small margin of error, and that is exactly what your seeing.

Salinity isn't that critical, as long as your close 1.024 to 1.026 it's fine. Heck I've had my salinity down to 1.022 for months without issues to my corals.

 

[homer1475]

This is one of those issues where to much information is worse then no information.