Related Clues:

• Primitive aquatic organisms
• Aquarium growth
• Pond scum and kelp
• Tiny pond plants
• Spy on the inside
• Pond accumulations
• Sea moss constituent
• Photosynthetic organisms
• Put in the ground
• Pond buildup
• Reef clingers
• Plankton components
• Pool life form
• Sea lettuce, e.g.
• Plankton component