Salinity Probe needs to be calibrated every week.

[Sacohen]

For the past month or so my Salinity Probe needs to be calibrated every week.

I did it last week when it was reading 28ppt and afterwards the same tank read 36 ppt.

It slowly starts dropping and today it was at 28 ppt again so I re calibrated it just now and it reads 37 ppt.

I've noticed that it has a heavy deposit of scaling on it.
This is probably due to the fact that the sump (where the probe is located) is where my ATO water (mixed with Kalkwasser) is distributed.

Could the scaling be effecting the probe reading?

Can I soak the probe in vinegar & water to remove the scaling or will the vinegar effect the probe's sensitivity?

Or could there be another reason for the drifting reading?



You can see at the end of the chart it was low (28) then I pulled the probe out re-calibrated and then it jumped up (37)

[rimai]

This is what the supplier said.

0.1 mol/L dilute hydrochloric acid (make up: 9 ml of hydrochloric acid diluted with water to 1000 ml) for 24 hours and washed with pure water, and then use electrode immersion fluid immerses 24 hours
If the passivation is serious, also can be soaked in 4% HF (HF) solution (3 ~ 5) s, washed with water, then soak in the electrode soaking liquid of 24 h

[Sacohen]

Thanks Roberto.

Can you check on the process to clean the pH and temp probes too. I might as well do all of them at once if it is the same.

I just don't understand why it would read fine after calibration and then drift. If it is because it is covered in calcium deposits it should be off all the time.

The pH and temp read fine and they are covered too.

[rimai]

They said same thing for pH, but I find that my pH probe reads fine even covered with coraline and algae.
Temp probes can be cleaned with anything. They are 100% enclosed in the metal sheath.

[Sacohen]

As I said mine does too, but I figured if I'm doing it I might as well do it for all my probes. It can't hurt.

Thanks for the help.

[Sacohen]

Cleaned the probe with Vinegar and it has been fine since then.