Cygnet - Phycomycin Algaecide - 50 LB BAG

Cygnet - Phycomycin Algaecide - 50 LB BAG
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Cygnet - Phycomycin Algaecide - 50 LB BAG

Temporarily Not For Sale
  • Not available until spring of 2019


  • For control of blue-green algae in lakes, ponds and drinking water reservoirs; irrigation, drainage and conveyance ditches, canals, laterals; estuaries, bayous, lagoons and more

Phycomycin is effective both as an algaecide (eliminating existing blue-green algae infestations) and as an algaestat (i.e., retarding and preventing new growth). It works quickly, and neither it nor its byproducts (hydrogen peroxide and oxygen) linger in the ecosystem.

Phycomycin's active ingredient, sodium carbonate peroxyhydrate, creates a powerful oxidation reaction that destroys algal cell membranes and chlorophyll, providing immediate control of algae. Fast-acting (within 60 seconds of application), it leaves behind no harmful residues and adds 13% bio-available oxygen to the water.

Active Ingredient: Sodium Carbonate Peroxyhydrate

For use on:

  • ponds
  • lakes
  • drinking water reservoirs
  • estuaries, lagoons
  • bayous
  • drainage and conveyance ditches
  • non-irrigation and irrigation canals
  • rivers and streams that are quiescent or slow moving

Weeds Controlled

  • Blue-Green Algae
  • See label for complete listing of weeds controlled


Floating and Emergent weeds: Shock Treatment Spring/Early Summer: Apply 15-40 LBS/ACRE-FT of water. Maintenance Treatments Every 2-4 weeks: Apply 8-25 LBS/ACRE-FT of water. Spot Treatment As needed. Can be applied to perimeter only: Apply 20-50 LBS/ACRE-FT of water.
When used at the labeled rates, Phycomycin will not harm fish (including sensitive fish such as rainbow trout), plants or aquatic life. Phycomycin is labeled for use up to 90 lbs. per acre foot of water. EPA approved and NSF/ANSI Standard 60 certified for drinking water application.

Begin application in spring as water temperature warms to 60º F and above. Early treatment when growth first appears or begins to create a nuisance will reduce the amount of Phycomycin you will need. Early treatment will also reduce the amount of dead growth.
Heavy, out of control growth may require more than one application or physical removal to gain control. For best results, use under conditions of minimal water flow. Apply early on the morning of a calm, sunny day.

See Label for complete application instructions.


  • Algae control is more easily achieved if treated soon after growth starts. Larger amounts of product may be needed to treat heavier blooms. As little as 2.5 LBS/ACRE-FT could be used for algaestatic treatment.
  • Decaying algae can deplete dissolved oxygen which can lead to fish kill, if excessive. Apply with 8 - 10 hours of daylight remaining. Do not reapply withing 48 hours. If treating a large lake or heavy bloom, treat 1/3 to 1/2 of the area and wait 2 - 3 das before treating remainder of water.
  • Causes irreversible eye damage and causes skin burns. Do not get in eyes, on skin or clothing. Wear goggles or face shield and rubber gloves when handling. Harmful if swallowed or inhaled. Avoid breathing dust.
  • When applying this product to water bodies, avoid solid particles from falling on nearby ground where birds and feed may be present. May be corrosive to beaks of birds

See Label for complete restrictions.

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