As it turns out the spraybars in at least two of the tanks are actually managing a very nice mist with this setup. I guess the holes are small enough that they do a good job of breaking the bubbles up into a nice fine mist which gets sprayed acros the tank. Since the CO2
flow is slow enough, it's a sporadic spurt of mist instead of a constant stream. That's okay with me as it means I don't have to look at quite as many bubbles in the water column.