Related Clues:
- A predator nearly pulled up seaweed, etc
- Kelp, for example
- Bit of aquarium scum
- Aquatic organism such as plankton
- What Aqua Chem is made to remove
- Bit of 19-Across flora
- Bit of birdbath gunk
- Simple marine plant
- Wee bit of marine life
- Simple pond life
- Pond scum organism
- Small bit of rootless flora
- A short bird hauled up deep plants
- Fountain growth
- Target of some pool treatments