Apex Salinity Probe

ab5ebdxer · 04/19/2019, 02:01 PM

I have made a mistake twice now with my auto top off, the first time I could not figure out how I did it but at least this time I have learned. The issues is that both times my APEX Salinity Probe did not properly track the slow fall in salinity. My auto exchange was taking out more salt then putting in. The probe only caught up after it was too late. Has anyone else had this issue, maybe something wrong with the settings of the probe? I have been very happy with APEX except the false sense of security in the probe, which finally I have learned to not trust, is not part of that joy.

I have attached the screen shot of the drop...this is a 630g tank that auto exchanges 5 gallons a day. I have included a picture of the APEX recording.

slief · 04/19/2019, 02:23 PM

Your probe should be placed in a dark area with good flow but it also needs to be devoid of microbubbles. It’s also wise to calibrate it every handful of months in addition to keeping the probe tip clean. Also making sure your temp compensation is enabled and the calibrations solution the same temp as the water where the temp probe is pretty critical. My guess is that your probe was either dirty, had microbubble accumulation in the tip or temp compensation was working properly. That or calibration wasn’t accurate. Another thing is making sure there are no electrical wires near the probe cable. Lastly stray voltage in the water can impact the probes accuracy and consistency.

ab5ebdxer · 04/19/2019, 02:45 PM

I have done the calibration and the conditions you describe is what I have done. I actually went to a talk on just the salinity probe at MACNA, which was interesting. I have been spot checking the probe to make sure it was correct but have gotten lazy at this since it seem to be correlating well the last few months. Not sure how the calibration would allow for such a sudden drop, I dont think the probe works that way. It did successfully catch a slow climb upward in my salinity about a month ago when I changed my flow rates of the internal pumps. I posted this in the Neptune form but no response yet. I could see the micro bubble issue possibly doing this. I think I will invest in a back up probe as well

04/19/2019, 02:23 PM	#2
slief RC Sponsor Join Date: Sep 2009 Posts: 14,173	Your probe should be placed in a dark area with good flow but it also needs to be devoid of microbubbles. It’s also wise to calibrate it every handful of months in addition to keeping the probe tip clean. Also making sure your temp compensation is enabled and the calibrations solution the same temp as the water where the temp probe is pretty critical. My guess is that your probe was either dirty, had microbubble accumulation in the tip or temp compensation was working properly. That or calibration wasn’t accurate. Another thing is making sure there are no electrical wires near the probe cable. Lastly stray voltage in the water can impact the probes accuracy and consistency. __________________ Director Customer Support Royal Exclusiv USA For All Royal Exclusiv & Bubble King questions please refer to our Sponsor forum: http://www.reefcentral.com/forums/fo...play.php?f=745 Current Tank Info: 480G display mixed reef, 90G sump, 90G refugium, 60G display refugium. Check out my build thread: http://www.reefcentral.com/forums/showthread.php?t=1783476

04/19/2019, 02:45 PM	#3
ab5ebdxer Registered Member Join Date: Oct 2003 Location: Canyon Lake, Texas Posts: 1,064	I have done the calibration and the conditions you describe is what I have done. I actually went to a talk on just the salinity probe at MACNA, which was interesting. I have been spot checking the probe to make sure it was correct but have gotten lazy at this since it seem to be correlating well the last few months. Not sure how the calibration would allow for such a sudden drop, I dont think the probe works that way. It did successfully catch a slow climb upward in my salinity about a month ago when I changed my flow rates of the internal pumps. I posted this in the Neptune form but no response yet. I could see the micro bubble issue possibly doing this. I think I will invest in a back up probe as well