Mine works great. I had issues to start.
Don’t use calibration packets. I think something is off in a real tank vs the packets. Also the “flow state” around the probe dramatically changes the reading.
You must have flow over the probe. Ideally straight up into it or straight down out of it (like the SPS kit). If you don’t have flow it will never work reliably. If you don’t want the kit and don’t have a sump with that kind of flow, just get a micro pump and point it towards the bottom of the probe.
Test your water… get it right where you want it. Use The method you trust. I use a Hanna tester. But if you like a refractometer.. or Milwaukee.. or floaty thing… use that. Get the tank to 35.
Once the tank is set to 35, start the calibration. I dip it in rodi, then gently blow on it a little, flick it, use a towel. Get it dry. Then do the dry part. For the 35 ppt part (or whatever the electrical value) just put it into the sump exactly where it will be. Let it sit for a minute, then start the wet part of the calibration.
If there are any odd issues, clean the probe. Citric acid dissolved in water. Let it sit for 30 min - 1 hour. Then swish it to get any gunk out. Rinse it in rodi a few times then do the calibration per above.
Very reliable with the above. Flow is key. Calibrating in tank is key.
The sensor has helped me many times. Had my awc source tube come out of the saltwater bin once… salinity dropped… bam saw it in apex. Had my skimmer over skim… salinity falls… saw it in apex. Filled my saltwater bin with rodi but forgot to add salt… saw it in apex.
