Possible disease need help please. New pic added

[Scavenger]

I agree with Christy, frag off the effected area. Candycanes normally are an easy frag and I've done so and they never even closed up much during the process so I don't think it stresses them much. Perhaps put the effected frag in a flow area where the snail would cast its mucus away from the frag.

You might even just reposition the existing colony to do the same, but I'd personally consider the fragging.