White stuff from yeast CO2 injector

I'm feeding the supply line from my yeast CO2 bottles into
the aeration venturi on the outlet of my powerheads. This
works fine for dissolving CO2 but there is a problem
with the venturi or the supply line itself getting plugged
with a white fungus-like growth. K.B. Koh first mentioned
this a long time ago. I don't know if he ever solved it.
It seems like the fungus growth is getting progressively
worse with time. It seems to plug up faster. I'm tempted
to dip the end of the PVC tubing and the whole outlet
housing assembly from the powerhead in bleach to kill off
the residue during cleaning. Any suggestions? (aside from
biting the compressed CO2 tank bullet)