Anyone know the way to monitor salt levels in the Water Softener?

Does anyone know the way to monitor salt levels in the water softener? I was going to build something using the ultrasonic sensor, but read that if the surface is not flat and perpendicular, the result will not be correct.

Any other way to do this?

The best way to do this that I’ve found is to build a scale – the lighter the bin is, the more salt you need. I watch it and put a threshold in there or something for alerts. I’m in the process of doing it myself right now using a set of load cells and wood. Take a look at this article about building a human scale, the load cells can handle 50kg so if you use four of them distributed you’re up to 200kg (440lbs). I figured that was plenty of margin for the salt bin.

Anyway, I constructed the thing and it works perfectly and is very accurate. I put a 10lb free weight on it and a 20lb free weight and calibrated it linearly and then stood on it and it showed what I expected. I don’t have a 3D printer so I tapped one of my friends at work who has one to print some load cell holders. I’m very excited to put it into use.

Very cool, thanks for sharing!

My water softener salt bin water fill level isn’t controlled well, so it fluctuates cycle to cycle and drifts over time. In your experience, how important is the water level on being able to distinguish the salt level?

In my bin, it isn’t important at all. My bin is probably 3.5 feet tall and about 12" round. The max water level line for brine is maybe 6-8" from the bottom so most of the area inside is filled with dry salt pellets. I have read online that you shouldn’t let the brine tank fall below 1/3 full which would still be above the max water level. I intend to figure out where 1/2 full is by weight and use that to determine when to trigger the “add a bag of salt” automation. I will likely also add a gauge to give more of an analog representation of the salt bin too.