Bubble counter fluid

[binford4000]

I am wondering what fluid people are using in there bubble counters. I have read to use baby oil,corn syrup and water. So now I am confused. What fluid is correct for our application and how far do you fill it??L looking forward to input. Tx

[AZDesertRat]

I have always used RO/DI water. Never had any issues wth it in 10 years of use. I have heard of people using mineral oil or vodka but never saw any reason to change.

[binford4000]

RO/DI makes sense. How far did you fill it ?

[AZDesertRat]

Pretty full with just a little headspace, maybe between 3/4 and 7/8 full. It lasts for months before I have to top it off.

[FlynnFish]

I filled mine with glycerin, the bubbles slowly float up. And I don't have to worry about algae growing in there from my fuge light.