So I picked up the EZSalt 3 based on this post. 
The problem is, when it got here, I couldn’t get my mac or my son’s windows computer to see the esp board in order to flash it. As it turns out, the issue was most likely the USB cable the sensor came with doesn’t support data, but during my frustration, I found a post from maybe a year ago where the guy who created the EZSalt sensor was hyping it up and said “you don’t have to use our software - it runs tasmota, so you can point it to whatever MQTT broker you want”…
I had no idea what tasmota or MQTT was, but I remember seeing MQTT in my HA Yellow somewhere - turns out, I did need their app in order to connect the sensor to my wifi, but once I did that, I was able to log into the local web server on the device (part of tasmota) and point it to the MQTT broker I setup on HA. From there, I was able to see the sensor in HA BUT there was a problem.
The sensor sends distance data in mm but states its in cm - that means the resulting distance is 10x bigger than it should be. Also, because I’m not using their app, the data is just distance. For me to turn it into a meaningful dashboard item, I needed to convert the distance into the proper units and into a meaningful number (amount of salt left, instead of distance from sensor to salt.
I created a helper sensor to address both - and now have a dashboard that looks very similar to yours.