I still can't entirely rap my head around what aquanut is saying, but I'd still like to give the vinegar thing a try just for the sake of having something else to fool around with. I'm having an awful time finding an IV flow control that can be ordered by an individual. I wonder if an irrigation drip emitter would work, I found one that has a pressure range of 7 to 50psi, that should give some room to play with a gravity feed I'd guess. Maybe add some control to the drip with one of those cheap tubing pinches they market for CO2 control in the aquarium. That's only a few dollars on the shopping list, some tubing, a few 2liters, vinegar and BS, and a check valve or two and the experiment should be in motion.