Quote Originally Posted by Ioannis View Post
Unless the sensor is well isolated with a special cable too, this is also a good option (Classic 4-20mA too).

But in general is in my opinion, better not to immerse anything electronics in the water. Keep them out, in an controlled place.

Ioannis
That is where snubbers come in handy to isolate the sensor. But a good stainless steel sensor should work with water just fine. I have used this type of thing with products ranging from a pH of 1 to 13.

Many options. What are the tank dimensions?