Salinity and Alk reading incorrect

[Robin316us]

Hi,
How to correct the reading in Apex Fusion. When I checked Hanna Alkalinity, the range is 8.75. But Fusion is 7.80. Same way for Salinity.. Fusion shows 31..but Hanna shows 1.025. A month ago both the Hanna and Fusion were almost same... But now way different. It happened when I went on vacation , the ato sensor was dirty and so no water was going to the sump. And the Sump was almost empty.. so when I came back from vacation, I filled the sump and cleaned the ATO sensor...but now my readings are different. How to solve this issue? TIA...

 

[Gtinnel]

I've been looking into it also because I've never had a reliable reading on salinity. It seems like it always gets blamed on electrical interference, or air bubbles in the probe. I get a fairly consistent reading for salinity it just isn't right, so I just use it to look for large swings. I guess you could try calibrating the probe, but thats never seemed to help me.

I always seem to have one reading that is off with the trident and I've read online that it is often caused by their calibration solution being wrong. I recently replaced the reagents and now I believe my calcium is reading high by at least 60. If you completely trust the Hanna I think you can just calibrate the trident with the value the Hanna checker shows.

 

[landlubber]

Hi,
How to correct the reading in Apex Fusion. When I checked Hanna Alkalinity, the range is 8.75. But Fusion is 7.80. Same way for Salinity.. Fusion shows 31..but Hanna shows 1.025. A month ago both the Hanna and Fusion were almost same... But now way different. It happened when I went on vacation , the ato sensor was dirty and so no water was going to the sump. And the Sump was almost empty.. so when I came back from vacation, I filled the sump and cleaned the ATO sensor...but now my readings are different. How to solve this issue? TIA...

this is the issue with using varying methods of measurement... discrepancy.
personally i'd stay the course with the hanna. As mentioned, probes can be affected by biofilm and airbubbles giving the hobbyist misleading readings which leads to chasing the true reading and not trusting anything.
In the case of salinity you need to have proper levels so a routinely calibrated refractometer is ideal. with Alk all you're aiming for is consistency. even if its 10dkh and you're under the impression its 8.5dkh its not a problem. it just needs to hold whatever reading you're getting.