Pool Salinity Sensor

I would like to be able to read the salinity (salt level) of my swimming pool via OH. My hope would be there is a sensor which could be attached to a Sonoff device that would report back over MQTT.

Anyone familiar with a senor that can read salt levels in water and could be easily connected to a Sonoff device?

I am already using the great Autelis plugin that Dan built for control of my pool pumps and lighting…Salt Level readings are not possible unless I purchase a new salt cell controller.

Any suggestions would be greatly appreciated.