Crossword Clue:

Bit of stagnant water growth

AnswerCrossword Clue
ALGABit of stagnant-water growth
GREENALGAEGrowth on wet rocks or the surface of stagnant water
ALGAStagnant water growth
AMOEBAInhabitant of stagnant water.
SCUMTop of stagnant water.
SCUMSurface of stagnant water.