Kalkwasser bucket level

[Vette67]

I have a 19 gallon feed and seed bucket that I fill and use to dose kalk into my tank. I have it set to dose about a gallon and a half of kalk a day using a hydros dosing pump. Everything works great, the pump doses on the schedule I have set up. The problem I have is that I would like to put a level meter in my kalk bucket to notify me when the bucket is low and needs to be refilled. I know I could use the fill level on the app, but I never really know exactly how much kalk water is on the bucket. I would like to use a triple optical sensor but the dust from the kalk has me worried that it would block the sensor. Only other thing I can think of would be to use a float switch. And of course, the caustic nature of kalk has me worried about it eating any sensors.

Does anyone have experience using a sensor in a kalk bucket and what have you found that works? Just curious about the best way to warn me that my kalk bucket is low.

Thanks…

Bill