Related Clues:
- Plant used in making biofuel
- Red tide cause
- Koi pond scum
- Aquarium bother
- A bird of prey almost picked up fish food?
- Several seaweeds good in salad uncovered close to shore
- Pool concern
- Some fish food
- Green growth in a pond
- Pond scum, typically
- Growth from stagnation
- Seaweeds tangled up in a gale
- Simple pond plant
- Organisms in birdbaths
- Plants with no roots or leaves