Refractometer

[hellasinc]

Hey guys,

Looking for some help cause I'm at my wits end, so I'm new to the hobby so any help would be greatly appreciated. The issue i have is my salinity keeps changing from 1.025 to 1.023 and I have no idea why. Example yesterday i mixed some red sea salt (blue bucket) for about an hour and then rose the temp to 25 degrees Celsius and left it for another hour to mix to get 1.025, changed the water and check the salinity and it was 1.025 . A couple of hours later I checked my tank again and still was 1.025 but when I check in the morning it was 1.023 and I don't know why and its not the first time its happened.

I have calibrated the refractometer with RO but my LFS gave me a bottle of Continuum Refractometer Reagent which when i use it my refractometer says 1.026 but the next day says 1.025 and now when I use RO water its no longer on the zero line which they recon it doesn't matter as long as when using the Continuum Refractometer Reagent the line stays on 1.025 or 1.026. So is the issue with my refractometer or is there something else going on ?

 

[Bruttall]

Water Temp can affect the meters reading of salinity.



Also a range of 1.023 to 1.026 is generally accepted as Ideal in the hobby.

 

[hellasinc]

Water Temp can affect the meters reading of salinity.



Also a range of 1.023 to 1.026 is generally accepted as Ideal in the hobby.

I understand that but it doesnt explain why salinity would drop from 1.025 when i checked my tank at night and the next day it reads 1.023 when the temp in the tank hasnt changed

 

[Bruttall]

Cheap Refractometer maybe?
This is what I use. Check Calibration with RO/DO 0-tds water every 6 months.

https://tinyurl.com/My-Refractometer

 

[Boehmtown]

My hand would always warm and mess up the refractometer. I ended up with a tropic marin floating hydrometer with a graduated cylinder. Beverly looking back

 

[Mr. Mojo Rising]

I would guess that your ATO is adding water (or water being added some other way), or your tester is inaccurate.

 

[Mr. Mojo Rising]

Turn your ATO off for a day, test it! The salinity should increase in the next 1-2 days, if it drops then you know the ATO is the problem. If the ATO is turned off, and the salinity still drop, then you know its the tester problem.

 

[hellasinc]

Turn your ATO off for a day, test it! The salinity should increase in the next 1-2 days, if it drops then you know the ATO is the problem. If the ATO is turned off, and the salinity still drop, then you know its the tester problem.

So turn off the ATO test salinity and then check salinity again 24 hours later ?

 

[Mr. Mojo Rising]

So turn off the ATO test salinity and then check salinity again 24 hours later ?

Yes turn it off. The evaporation will increase the salinity, but its slow and takes 1-2 days to show on your tester, leave the ATO off for a few days and track the salinity increase for a bit. If the salinity increases or decreases should make it clear if the problem is the ATO or the tester. Good luck

 

[hellasinc]

Yes turn it off. The evaporation will increase the salinity, but its slow and takes 1-2 days to show on your tester, leave the ATO off for a few days and track the salinity increase for a bit. If the salinity increases or decreases should make it clear if the problem is the ATO or the tester. Good luck

sounds good thank you

 

[ScottJ]

Hey guys,

Looking for some help cause I'm at my wits end, so I'm new to the hobby so any help would be greatly appreciated. The issue i have is my salinity keeps changing from 1.025 to 1.023 and I have no idea why. Example yesterday i mixed some red sea salt (blue bucket) for about an hour and then rose the temp to 25 degrees Celsius and left it for another hour to mix to get 1.025, changed the water and check the salinity and it was 1.025 . A couple of hours later I checked my tank again and still was 1.025 but when I check in the morning it was 1.023 and I don't know why and its not the first time its happened.

I have calibrated the refractometer with RO but my LFS gave me a bottle of Continuum Refractometer Reagent which when i use it my refractometer says 1.026 but the next day says 1.025 and now when I use RO water its no longer on the zero line which they recon it doesn't matter as long as when using the Continuum Refractometer Reagent the line stays on 1.025 or 1.026. So is the issue with my refractometer or is there something else going on ?

Also, don't calibrate the refractometer with RODI water, calibrate with the calibration solution. It will say on the bottle what salinity it is at, usually 35ppt.

I have a refractometer from BRS that I have to calibrate EVERY TIME I use it. I'll check the tanks upstairs, carry the refractometer in its padded case downstairs to where my mixing station is, check it with the calibration fluid, and it will have changed. So I am just in the habit of calibrating every time I take it out of it's case.

 

[hellasinc]

Also, don't calibrate the refractometer with RODI water, calibrate with the calibration solution. It will say on the bottle what salinity it is at, usually 35ppt.

I have a refractometer from BRS that I have to calibrate EVERY TIME I use it. I'll check the tanks upstairs, carry the refractometer in its padded case downstairs to where my mixing station is, check it with the calibration fluid, and it will have changed. So I am just in the habit of calibrating every time I take it out of it's case.

2 questions, firstly i have done that but it keeps changing from 1.025 to 1.025 is there a issue with the solution? Also if i use the solution then i use RO water the line on the refractometer is no longer on zero

 

[ScottJ]

2 questions, firstly i have done that but it keeps changing from 1.025 to 1.025 is there a issue with the solution? Also if i use the solution then i use RO water the line on the refractometer is no longer on zero

1 Not sure what you mean. Could you clarify?

2 Don't worry about what the refractometer reads with fresh water. It does not measure fresh water, it measures saltwater.

 

[hellasinc]

1 Not sure what you mean. Could you clarify?

2 Don't worry about what the refractometer reads with fresh water. It does not measure fresh water, it measures saltwater.

Sorry what i meant is when I use Continuum Refractometer Reagent it says 1.026 however the next two days the refractometer says 1.025 is this a issue ?

 

[ScottJ]

Sorry what i meant is when I use Continuum Refractometer Reagent it says 1.026 however the next two days the refractometer says 1.025 is this a issue ?

Are you calibrating, turning the screw on the refractometer, and then the next time it's reading different? If so, that's why you need to calibrate every time you use it.

Personally, I wouldn't worry about the difference between 1.025 and 1.026.

 

[hellasinc]

Are you calibrating, turning the screw on the refractometer, and then the next time it's reading different? If so, that's why you need to calibrate every time you use it.

Personally, I wouldn't worry about the difference between 1.025 and 1.026.

Yeah so i use it all the time but one ill put it to 1.026 turning the screw you mentioned and for some reason the day after when i use the solution again its says 1.025, so I'm guessing ill have to calibrate to 1.026 each time im going to use it ?

 

[ReneReef]

The ATO is good point to investigate.

Something else is to make sure that you store and use the refractometer at the same ambient temperature.

So, don’t store it in a cold garage and measure in a warm room. Or store it in a warm room and walk outside in the cold for light to take the measurements.

Such changes mess with the ATC too much. That will make your measurements drift and the refractometer loose calibration.

 

[ScottJ]

Are you calibrating, turning the screw on the refractometer, and then the next time it's reading different? If so, that's why you need to calibrate every time you use it.

Personally, I wouldn't worry about the difference between 1.025 and 1.026.

Yeah so i use it all the time but one ill put it to 1.026 turning the screw you mentioned and for some reason the day after when i use the solution again its says 1.025, so I'm guessing ill have to calibrate to 1.026 each time im going to use it ?

Yes you have to calibrate each time you use it.

 

[Staghorn]

Just calibrate it as often as you need to make sure it matches your calibration solution. The reason you may be getting a different reading at zero is because if there is even if the refractometer is off by a little bit, that little bit is magnified by the time it travels all the way from 1.026 to zero. That’s why it’s recommended to calibrate it as closely to the salinity in the aquarium so there won’t be such a large discrepancy. Lots of things make them lose calibration, but as long as you calibrate it frequently, you should be OK. As far as the salinity in your aquarium changing overnight. It really depends on your water volume. If it’s a nano or pico tank, it could greatly overnight. The larger the water volume the less possibility there is to have that large of a change.

 

[Randy Holmes-Farley]

Also if i use the solution then i use RO water the line on the refractometer is no longer on zero

That is normal and expected for any refractometer sold to hobbyists that is not stated to be a true seawater refractometer. It should not read 0 properly.