White Slime Blocking The Hole On My Co2 Ladder

[Alps]

What is this stuff? Its like a whitish slime that just grows all over the bubble entry hole (bottom) of the nutrafin bubble ladder. It seems like there is a light layer of this stuff along the rungs of the ladder, but there is a big beard of it by the bubble entry hole which causes the bubbles to jump out of the ladder right when they come out of the silicon tubing.

thanks for the help