I've been having a terrible time with the vulcanoes myself. I have about 120 different colors, and it seems that some colors work better in the bed than others. Do the fluid beds you buy get these vulcanoes as well? I'm almost thinking that if you were to use a smaller diameter PVC fitting, maybe 1.5" rather than 2 it would work better? Air is going to take the path of least resistance through a coffee filter, so if it has less opportunity to stray and force itself through the easy spots, maybe it would work better?