Tunze Osmolator ATO optical sensor fail

[MorganAtlanta]

I'm having a problem with my Tunze Osmolator ATO optical sensor failing to sense low water and letting the sump run low about once a month. I've got a low water float switch and alarm on my Apex that alerts me to the situation. When it happens, I can usually just splash some water on the optical sensor and/or unplug and replug the ATO controller and it will recognize the low water. It's been fine because I've been home pretty much every day for the last year, but I do have some travel coming up, and it would be a bit more serious problem if I was out of town. Has anyone else run into this? Is it likely just a bad sensor?

 

[lapin]

I cant say if its out of the water all the time it does not happen.
My sensors gets submerged when my external skimmer is off, which is for about 8 hours per day. I get the overfill alarm lights which is ok (I have it on silent).
Once in awhile mine thinks its full and does not refill the sump to the proper level. A swish of a brush to clean it off usually does the trick.

 

[MorganAtlanta]

The problem is if I'm out of town, there's no one to give it a swish of a brush. I thought the point of optical sensors was that they failed less often than float switches, but that's not my experience so far.

 

[LegendaryCG]

How’s your magnesium? If it gets low calcium carbonate can precipitate on equipment like optical sensors causing issue.

 

[SPR1968]

I would give it a clean with some vinager, leave it to soak for a few minutes and then wipe it clean

Check there aren’t any bubbles being produced around were it’s located as micro bubbles can affect it

Also just check you arnt getting any debris stuck near the sensor in the holder. I once had a tiny piece of debris wedged in between the sensor and holder and it did the same thing and didn’t top up

Ive actually got a reminder in Apex to remind me to wipe the Tunze and Apex ATK sensors down every 2 months

 

[bblumberg]

I have had Tunze sensors fail over the years and not respond even after a vinegar cleaning. Roger at Tunze USA replaces them for ~$35.

 

[MorganAtlanta]

Mag is around 1350. I'm not seeing signs of precipitation anywhere, and no micro bubbles as best I can tell. Thanks for the replies. I might try a replacement just to see if the sensor is the problem.