Antifouling target on a keel, 4 letters
Bit of aquarium growth, 4 letters
Bit of aquarium gunk, 4 letters
Bit of phytoplankton, 4 letters
Bit of pond vegetation, 4 letters
Bit of rootless flora, 4 letters
Bit of seafloor flora, 4 letters
Bit of water growth, 4 letters
Blue-green birdbath bit, 4 letters
Chlorophyll-containing microorganism, 4 letters
Chlorophyll-containing organism, 4 letters
Chlorophyllous organism, 4 letters
Chlorophyllous plant, 4 letters
Component of a lichen, 4 letters
Eukaryotic organism, 4 letters
Foot of a food chain, 4 letters
Fragment of pond scum, 4 letters
Frog spit, for example, 4 letters
Giant kelp, for one, 4 letters
Green ___ (spirogyra, e.g.), 4 letters
It creates energy through photosynthesis, 4 letters
Microscopic organism, 4 letters
Microscopic pond organism, 4 letters
Microscopic sea life, 4 letters
Morsel for a sea snail, 4 letters
Part of a pond problem, 4 letters
Part of many a snail's diet, 4 letters
Plant that's often pluralized, 4 letters
Pond scum component, 4 letters
Primitive water organism, 4 letters
Primitive water plant, 4 letters
Red ___ (marine plant), 4 letters
Red or brown organism, 4 letters
Rootless pond plant, 4 letters
Rootless water life, 4 letters
Sea lettuce, for one, 4 letters
Sea moss constituent, 4 letters
Simple aquatic organism, 4 letters
Simple aquatic plant, 4 letters
Simple water dweller, 4 letters
Snack for a surgeonfish, 4 letters
Spirogyra or frog spit, 4 letters
Stagnant water growth, 4 letters
Stagnant water problem, 4 letters
Stonewort or rockweed, 4 letters
Unwanted aquarium collection, 4 letters
Unwanted aquarium organism, 4 letters
Unwanted organism in an aquarium, 4 letters
Unwanted plant in a pool, 4 letters
Unwanted pool organism, 4 letters
Unwanted swimming pool bit, 4 letters
___ bloom (sight along a beach), 5 letters
A Berkeley scientist has figured a way to make hydrogen fuel from these, 5 letters
Antifouling chemical target, 5 letters
Aquarium accumulation, 5 letters
Aquarium cleaner's problem, 5 letters
Aquarium microorganisms, 5 letters
Aquarium owner's bane, 5 letters
Bane of pool owners, 5 letters
Basis of the marine food chain, 5 letters
Big oxygen producer, 5 letters
Blue-green organisms, 5 letters
Bottom of the ocean's food chain, 5 letters
Bottom-of-the-food-chain organisms, 5 letters
Cause of pool problems, 5 letters
Certain thallophytes, 5 letters
Chlorine prevents it, 5 letters
Fish tank plant life, 5 letters
Food source for some marine life, 5 letters
Fungi + ___ = lichens, 5 letters
Green buildup in an aquarium, 5 letters
High-yield biodiesel source, 5 letters
It made lake TOO green, 5 letters
It may fill up your tank, 5 letters
It's found in ponds, 5 letters
Kelp beds, essentially, 5 letters
Low end of the food chain, 5 letters
Organism that can be brown, red or green, 5 letters
Photosynthetic organisms, 5 letters
Phycologist's study, 5 letters
Pond cover, frequently, 5 letters
Pond scum and seaweed, 5 letters
Pond surface growth, 5 letters
Pool maintenance bane, 5 letters
Pool owner's concern, 5 letters
Pool owner's headache, 5 letters
Pool owner's nuisance, 5 letters
Pool owner's problem, 5 letters
Pool treatment target, 5 letters
Potential pond poisoner, 5 letters
Primitive aquatic organisms, 5 letters
Rootless life of the sea, 5 letters
Sargasso Sea floaters, 5 letters
Seaweed and kelp, e.g., 5 letters
Seaweed, for example, 5 letters
Sign of an untreated pool, 5 letters
Simple aquatic organisms, 5 letters
Single-celled plants, 5 letters
Slimy aquarium growth, 5 letters
Stagnant-water buildup, 5 letters
Stuff studied on a grade school trip to the pond, 5 letters
Swimming pool concern, 5 letters
Swimming pool problem, 5 letters
Uninvited pool guests, 5 letters
What agar is derived from, 5 letters
With fungi, they form lichens, 5 letters
What did the mathematical mermaid buy at Victoria's Secret?, 9 letters
What mathematical mermaids wear?, 9 letters
Helpful aquarium fish, 10 letters
The scourge of one-celled supervillains everywhere, 8 letters
Concerning certain seaweeds, 5 letters
Like diatomaceous earth, 5 letters
Like some pond growth, 5 letters
Like some pond life, 5 letters
Like some pond vegetation, 5 letters
Related to seaweeds, 5 letters
Garth's last name in Wayne's World, 5 letters
Garth's surname, in Wayne's World, 5 letters
Portugal's holiday coast, 7 letters
Photosynthetic plants, 5 letters
Mesquite pod used in tanning and dying, 11 letters
Mesquite of Gulf Coast and Caribbean islands from Mexico to Venezuela, 9 letters
Long pod containing small beans and sweetish edible pulp, 9 letters
Used as animal feed and source of a chocolate substitute, 9 letters
Evergreen Mediterranean tree with edible pods, 9 letters