Cobweb Mold
Hypomyces/Cladobotryum spp.
Appears as grey, wispy strands hovering above the substrate. Its defining characteristic is speed — a dime-sized patch can cover an entire tub in 24–48 hours.

Visual Identification
Grey, wispy, cotton-candy-like strands hovering above the substrate surface. Much lighter and more ethereal than mushroom mycelium.
Treatable
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