Light Attenuation

Impart color to water to reduce light penetration and suppress submersed plant growth


  • 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