Slime in Water Reservoir

[lycaonpictus]

I have a two gallon reservoir in my wardian case in which floats an ultrasonic mister. The orchids seem to love it so far (I haven't had it that long).

I've found, however, that a clear sort of slime quickly forms on the inside surface of the container (below water line) and on the mister / float. Every few days I wash everything off and fill with fresh water, but it tends to come back just as fast.

Not a problem, really, since it's a small reservoir and a small collection. I was just wondering if anybody else had experienced this, and what possible solutions were out there.

Thanks!