Planktonic Algae Identification & Treatment
Category: Algae — Microscopic Tier: 1 — High-Priority
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Identification
Planktonic algae are microscopic, single-celled organisms that turn water green, brown, or reddish when abundant. They cannot be individually seen without a microscope. "Pea soup" green water is a planktonic algae bloom.
Key distinguishing features:
- Water appears uniformly green, brown, or reddish — not patchy or stringy
- Cannot see individual organisms — water looks like colored liquid
- A jar of pond water held up to light appears translucent green
- Does not feel slimy or stringy when rubbed between fingers
Commonly confused with: Duckweed (surface coating of tiny green plants, not dissolved in water), filamentous algae (stringy/slimy mats, not dissolved), Euglena blooms (bright green, often concentrated at surface)
Treatment
Recommended Natural Waterscapes Products:
- Copper-based algaecides (Cutrine Plus) — Fast-acting algaecide that kills planktonic algae on contact.
- Beneficial Bacteria — Reduces organic nutrients that fuel algae growth. Pond Cleanse Bacteria
- Pond Dye (Vivid Blue) — Limits light penetration. Vivid Blue Pond Dye
- Aeration — Circulates water and increases dissolved oxygen. Aerators
Long-term strategy: Planktonic algae blooms are driven by excess phosphorus and nitrogen. Reducing nutrient inputs is the only permanent solution.
IMPORTANT: Some planktonic blooms are cyanobacteria. See Blue-Green Algae for safety information.
Full Profile
- Native Range: Ubiquitous worldwide
- US Distribution: All 50 states, all EPA ecoregions
- Ecological Benefits: Planktonic algae form the base of the aquatic food chain. A moderate level is essential for a healthy pond. Complete elimination is neither possible nor desirable.
- Seasonal Behavior: Blooms most common late spring through early fall.
Sources: Texas A&M AquaPlant – Planktonic Algae
Related
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