I disagree with the above responses. A gas seperator can be used as a bubble counter. Many, many people do this. The bubble counter would do this, but would be harder to clean the gunk out of. IF you do want to use a bubble counter, make sure to use bubble counter fluid, or mineral oil, and make sure it is fastened so it can't tip and let it into the tank. I use check valves before and after the bubble counter.