Considerations

• Not selective in that all submersed plant species may be affected
• May select for invasive plants like hydrilla that needs less light than most native plants
• May be cost prohibitive for large water bodies
• Water body needs to be sufficiently deep for dyes to exclude light and be effective
• Difficult to sustain appropriate concentration in flow through waters
• Commercial blue dyes are available
• Natural tannins can be concentrated but black or brown may be aesthetically unpleasing

Examples of Feasible Control

• Dyes are applied to small ponds to impart pleasing blue color and impede submersed plant and algae growth