Non-contact sensor issues

[mginster]

I am using these NC sensors with reef-pi / Robotank.

Edit: guess Amazon links dont work....its a XKC-Y25V named

Taidacent Non Contact Liquid Level Sensor Contactless Water Tank Water Level Sensor for Tank Water Level Control with Low and High Level Output​

Amazon product ASIN B07FC5RGC7
I have them setup properly and they work. My rodi tank one works to notify me when it needs refilling. However, the ones actually controlling an ATO / high sump / low sump have issues due to the nature of a sump vs clean rodi tank.

If my sump has any film on it (even a nearly spotless side wall) it does not detect when water is missing. I tested by pulling out cups of water to drop the level of the sump and it was about 2 inches lower than the edge of the sensor and still thought there was water present. The second I wiped the inside of the sump with a paper towel to clean the film, it triggered as missing water.

Note: My acrylic sump sidewall is only about 1/4" thick.

Is this a common theme with all NC sensors or did I just buy crappy ones? I am ordering regular old float switches to setup as those are tried and true with all the homemade ATO's ive made.

 

[Sral]

That’s unfortunate … the ones I found on Amazon.com have an adjustment screw behind the back cover, have you tried that ? You might need to make them a bit less sensitive, so they don’t get triggered by the film itself.

 

[mginster]

Thank you, didnt know that existed.