Pond Logic® Algae Defense® Algae Control
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$39.99 - $49.99


This item ships via motor freight and may arrive separate from the rest of your order
This item ships from the manufacturer and may arrive separate from the rest of your order
Live Koi ship from our hatchery and may arrive separate from the rest of your order
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Plants are held in accordance to climate zones. Click for ship dates.
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This item carries an additional handling charge of $ per item
4+ $34.99 Each - Gallons

  • Details
  • Usage
  • Weeds Treated
  • Videos
  • Reviews
  • Eliminate Algae Quickly
  • Fast Acting Liquid Formula
  • Spray Directly Onto Algae Blooms

Eliminate algae blooms and green water from your pond with Pond Logic® Algae Defense®. A fast-acting liquid formula, Algae Defense® can be directly applied via a pressurized sprayer to combat floating filamentous algae, bottom growing chara or the planktonic algae that causes green water. Each gallon of Algae Defense® treats up to 8,000 square feet and can be used when water temperatures are at or above 60°F.

Pond Logic® Algae Defense® can also be found in the ClearPAC and ClearPAC PLUS All-in-One Pond Care Packages.

Usage Information

From dosage rates to product labels, the USAGE tab contains all of the information you need to properly apply your pond care products.

Pond Logic Algae Defense
1 Gallon
Application Liquid
Temperature Restriction Use When Above 60°F
Square Footage Per Gallon Up to 8,000 Square Feet
Shelf Life 2 Years

Dosage Rates

Treatment Area
Algae Defense®
Treatment Booster™ PLUS
1,000 Square Feet 1/2 Quart (16 Ounces) 1-1/4 Gallons 4 Ounces
2,000 Square Feet 1 Quart (32 Ounces) 2-1/2 Gallons 6 Ounces
4,000 Square Feet 2 Quarts (64 Ounces) 5 Gallons 12 Ounces
8,000 Square Feet 4 Quarts (1 Gallon) 10 Gallons 22 Ounces

Please note: Above are recommendations. Always read the product label.

How To Apply Algae Defense®

Mix the amount of Algae Defense® and Treatment Booster™ PLUS (if using) with pond water in a tank sprayer according to label instructions. Use a pressurized pond sprayer to spray the Algae Defense® mixture directly onto to the target algae. Treat only up to half of the pond's surface and wait 10-14 days before a second treatment. In hot weather or when fish are stressed, treat only 1/4 - 1/3 of the pond's surface at a time. Over time, the algae will begin to brown and die. Once it is completely dead, use a rake, like the Pond & Beach Rake, to remove dead algae away to prevent an accumulation of dead algae and muck.

When To Apply Algae Defense®

Algae Defense® should be applied when algae is actively growing. Begin applications when algae first appears. Unless steps are taken to reduce the overall nutrients in the pond, multiple applications may be needed for full season algae control. Use with Treatment Booster™ PLUS for best results.


Do not use in ponds with koi, goldfish, grass carp, or trout, unless carbonate hardness is above 50ppm.


Weeds Treated

The first step towards effectively treating any pond weed is proper identification. Pond Logic® Algae Defense® Algae Control is recommended for use against each of the weeds listed below. Click on your desired weed for more information and alternate control options.

  • Chara
  • Filamentous Algae
  • Planktonic Algae
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What others are saying

4 out of 5

Customer Rating

"review"Robert Smitth of Flint, MI

for the price its a good item, didnt like spraying under the water, but killed my alergy quick

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5 out of 5

Customer Rating

"Amazing!!!"Kay Foutz of Waukee, IA

As suggested...I used with the surfactant and how AMAZING the products are. Fast acting too. Got rid of the green icky stuff and now the water is so clear and inviting.

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3 out of 5

Customer Rating

"Algaecide"Felix Felde of Bend, OR

We used Algae Defense with Cide Kick on our pond, and after two applications, the algae is only slightly improved. Unfortunately, we learned that hard way that this stuff kills frogs and tadpoles. ALL of them.

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5 out of 5

Customer Rating

"Very amazing"Tom Irish of Bagley, WI

I used this product on our pond and this is the first time in 25 years that someone has swam in the pond. All the kids say thank you Pond Guy. Also the pond dye is a great product!!

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