Salinity drop 0.5 ppt per day

[Quentin05]

Hello,

For about 2 weeks I have had my salinity drop at a level of 0.5 ppt per day.

I did a water change to creep it back up slowly and it went back down again.

I am using the Hanna salinity meter that I calibrated with its solition. I don't see any visible leak. O use a tunze 9004 skimmer and I my skimmage is pretty wet but the cup takes a good 2 week to fill (and it is a very small cup). My salt creep os pretty inimal. I ordered a cheap refractometer pen on Amazon to have a second measuring device.

I have a JBJ 45 gallons. I did not add anything recently, and my ATO keeps the level the same.

Let me know if there is anything else I should look for.

 

[ShakeyGizzard]

Hello,

For about 2 weeks I have had my salinity drop at a level of 0.5 ppt per day.

I did a water change to creep it back up slowly and it went back down again.

I am using the Hanna salinity meter that I calibrated with its solition. I don't see any visible leak. O use a tunze 9004 skimmer and I my skimmage is pretty wet but the cup takes a good 2 week to fill (and it is a very small cup). My salt creep os pretty inimal. I ordered a cheap refractometer pen on Amazon to have a second measuring device.

I have a JBJ 45 gallons. I did not add anything recently, and my ATO keeps the level the same.

Let me know if there is anything else I should look for.

If you use a roller filter it removes saltwater from the sump, its minimal but it does it

 

[Quentin05]

If you use a roller filter it removes saltwater from the sump, its minimal but it does it

No roller, it is a JBJ 45, it is AIO. My wild guess is bad salinity checker but it is weird that it shows a constantly dropping salinity rather than just an off reading. I might just invest in the Tropic Marin big glass tube tbh.

 

[EnterName]

No roller, it is a JBJ 45, it is AIO. My wild guess is bad salinity checker but it is weird that it shows a constantly dropping salinity rather than just an off reading. I might just invest in the Tropic Marin big glass tube tbh.

Had the same issue, it's probably the electrodes that need some cleaning. Place the salinity meter in some vinegar/acetic acid or dilute HCl (2-3%) for a few minutes. You can also use very fine sand paper for the black carbon electrode (just the top layer!). Afterward the calibration might be off, but you can use Randy's DIY salinity standard (the conductivity standard at the bottom) to calibrate the meter if you don't have the 35ppt Hanna ones anymore. Regardless of which calibration solution you use, make sure it is at precisely 25°C/77°F as the temperature compensation does not seem to work well on the Hanna salinity meter.

 

[Quentin05]

Had the same issue, it's probably the electrodes that need some cleaning. Place the salinity meter in some vinegar/acetic acid or dilute HCl (2-3%) for a few minutes. You can also use very fine sand paper for the black carbon electrode (just the top layer!). Afterward the calibration might be off, but you can use Randy's DIY salinity standard (the conductivity standard at the bottom) to calibrate the meter if you don't have the 35ppt Hanna ones anymore. Regardless of which calibration solution you use, make sure it is at precisely 25°C/77°F as the temperature compensation does not seem to work well on the Hanna salinity meter.

Thank you will try that

 

[ShakeyGizzard]

No roller, it is a JBJ 45, it is AIO. My wild guess is bad salinity checker but it is weird that it shows a constantly dropping salinity rather than just an off reading. I might just invest in the Tropic Marin big glass tube tbh.

I use a refractometer and calibration fluid. I just keep all new batches and the tank the same. It reads 1.026 (35 ppt) may be slightly off compared to another tester, but everything stays the same for stability.

 

[Randy Holmes-Farley Verified Community Expert]

Just in case it is not clear to any reader, salinity cannot ever change on its own. If it is a real change, then salt water is being removed somehow and replaced by fresh, or the tank water volume is rising by adding fresh water.

 

[Quentin05]

Just in case it is not clear to any reader, salinity cannot ever change on its own. If it is a real change, then salt water is being removed somehow and replaced by fresh, or the tank water volume is rising by adding fresh water.

I used the cleaning technique the previous answer mentioned and the reader showed something totally off like 38 ppt. So now I am 99% sure it was a failed maintenance on my salinity reader. I have a tropic marin glass tube hydrometer on the way.

 

[EnterName]

I used the cleaning technique the previous answer mentioned and the reader showed something totally off like 38 ppt. So now I am 99% sure it was a failed maintenance on my salinity reader. I have a tropic marin glass tube hydrometer on the way.

Glad I could help!

Of course you will need to re-calibrate it now, but if you make sure the calibration solution is at 25°C/77°F it should be as good as new and give very precise (and stable) readings :)

 

[Ziggy17]

If you use a roller filter it removes saltwater from the sump, its minimal but it does it

Are you referring to the water that gets absorbed into the fleece?

 

[Ziggy17]

I used the cleaning technique the previous answer mentioned and the reader showed something totally off like 38 ppt. So now I am 99% sure it was a failed maintenance on my salinity reader. I have a tropic marin glass tube hydrometer on the way.

The TM hydrometer is the best $40 you will spend in the hobby.

 

[Joe31415]

Just in case it is not clear to any reader, salinity cannot ever change on its own. If it is a real change, then salt water is being removed somehow and replaced by fresh, or the tank water volume is rising by adding fresh wate

An ATO and an AWC that's removing more water than it's adding is a good way for that to happen.
I know I've had times where, for one reason or another*, the AWC didn't fill the tank back up and the ATO finished the job.

*IME, assuming it was working correctly at some point, that usually means a cracked tube in a peristaltic (fill) pump, pump calibration drifted or a timer/sensor that took the night off. I suppose it's probably also worth making sure nothing is accidentally siphoning water back out. And, now that I write all that, I'd say one thing OP could do is, if they have an ATO, see if it's going through more water than expected.

 

[KrisReef]

I had this cat that was determined to get to the fish in my reef. She drank saltwater when I was busy doing other things until one day her kidneys failed.

If your salinity is dropping I would check the cat because salt doesn’t evaporate.

 

[Ziggy17]

I had this cat that was determined to get to the fish in my reef. She drank saltwater when I was busy doing other things until one day her kidneys failed.

If your salinity is dropping I would check the cat because salt doesn’t evaporate.

Did the salt water give the cat super powers, or just kidney failure? Cause acquiring cat super powers is probably worth the renal failure.

 

[KrisReef]

Did the salt water give the cat super powers, or just kidney failure? Cause acquiring cat super powers is probably worth the renal failure.

Not sure what it gained but I did see it shed it’s skin like a serpent as it slinked off.

 

[vetteguy53081]

Hello,

For about 2 weeks I have had my salinity drop at a level of 0.5 ppt per day.

I did a water change to creep it back up slowly and it went back down again.

I am using the Hanna salinity meter that I calibrated with its solition. I don't see any visible leak. O use a tunze 9004 skimmer and I my skimmage is pretty wet but the cup takes a good 2 week to fill (and it is a very small cup). My salt creep os pretty inimal. I ordered a cheap refractometer pen on Amazon to have a second measuring device.

I have a JBJ 45 gallons. I did not add anything recently, and my ATO keeps the level the same.

Let me know if there is anything else I should look for.

generally salt goes up thru evaporation. Only was would be addition of water daily or false reading

 

[Quentin05]

generally salt goes up thru evaporation. Only was would be addition of water daily or false reading

False reading loojs to be the answer. TM hydrometer coming my way.

 

[Randy Holmes-Farley Verified Community Expert]

False reading loojs to be the answer. TM hydrometer coming my way.

I know it is very trendy to want the TM hydrometer, but a properly calibrated conductivity probe is both easier to use, has uses the hydrometer cannot perform (such as kalkwasser potency) , and is what chemical oceanographers use.

The only advantages of the TM hydrometer are cost, and that, assuming it was originally manufactured correctly, it cannot be miscalibrated by the user.

 

[Biokabe]

I know it is very trendy to want the TM hydrometer, but a properly calibrated conductivity probe is both easier to use, has uses the hydrometer cannot perform (such as kalkwasser potency) , and is what chemical oceanographers use.

The only advantages of the TM hydrometer are cost, and that, assuming it was originally manufactured correctly, it cannot be miscalibrated by the user.

How do the conductivity probes that oceanographers use compare to our hobbyist equipment?

Are they using the same, often finicky probes that we use (and are just better at using them correctly due to more experience), or are there lab-grade versions that are more reliable long-term?

I realize that my tone comes off as somewhat combative, but it's not intentional - just genuinely curious, as the big complaint I've heard about conductivity probes is that they're difficult to keep calibrated long-term.

 

[vetteguy53081]

False reading loojs to be the answer. TM hydrometer coming my way.

Calibrate unit depending on what you are using and even take a water sample to an lfs that uses a digital unit or hydrometer and see what reading they get