Apex salinity probe shows steady drop, then back to normal

[itgoeson]

I set up my Apex a little over 2 weeks ago. The salinity probe took some doing to calibrate in the beginning, but it has been pretty close to my Tropic Marin hydrometer since getting it calibrated (1.0257 TM, 1.0252 Apex).

Tonight we were at a dinner out of state when my phone threw a notification that the salinity was low. Over 2.5 hours, the salinity steadily dropped. I called a neighbor and she went to check things out - I thought maybe my ATO had stuck on. She took a look and found no problems. She unplugged the ATO just in case but touched nothing else.

As soon as she left, the salinity reading jumped back to normal (a little higher, but basically normal).

What could cause this? After watching Terence’s interview about his house fire, this whole thing took years off my life and I’d like to prevent it from happening again…?

 

[slythy]

Air bubbles will do that. If you changed socks or had an overflowing so k near by you can get those until it finds its way out

 

[Lbrdsoxfan]

Air bubbles, electrical interference, 3/4 moon... All those things and more will cause misreadings. The salinity probe is a small step above utter garbage, outside of a cursory glance, I wouldn't trust it as a single point of reference.

 

[TheHarold]

A power flicker/brief outage has a similar effect on my Apex units.

 

[All_talk]

Air bubbles, electrical interference, 3/4 moon... All those things and more will cause misreadings. The salinity probe is a small step above utter garbage, outside of a cursory glance, I wouldn't trust it as a single point of reference.

I would say its maybe a full step above utter garbage, verging on almost useful. :) But I agree, you will want to check it against a standard you trust regularly.

I got mine tuned in pretty well a couple of weeks ago, its been good since then, but time will tell. I don't have any alarms set on it at this point, if it works well longer term I might.

As he OP has learned, it may not be a good way to judge what the ATO is doing. If you want some monitoring of the ATO there are options with the Apex.

 

[itgoeson]

I have the probe under some rock in a section of the sump that has no turbulence - I’m not sure how it could be getting bubbles, though I bet that is the issue! Should I wrap it in foam?? It worked perfectly for a few days but has been finicky today - dropped briefly then shot higher than accurate most of the rest of the day. It’s a shame to ignore it entirely. I moved it away from the other probe wires, etc. it’s as far from the return pump and skimmer as it can be, but I’m not sure how close is too close for this to be electrical interference?

 

[radfly]

Snail on the sensor.

 

[All_talk]

I suspect you will have better luck with it an area with more flow.