Best Lily Pad Killer For Ponds: Compare 10 Aquatic Herbicides

#1 · Best Overall

1. Crystal Blue CattPlex Pro

• Weight: 2 lb
• Form: Spray

Best for: Water-lily and cattail control.

Why it ranks #1: Its verified target list explicitly includes water lily, and the 32-ounce spray is formulated for use around people, pets, and wildlife, subject to label restrictions.

CattPlex Pro explicitly targets water lilies alongside cattails, phragmites, water hyacinth, and other aquatic growth, making it a direct option when a pond has mixed plant problems. Its spray form suits buyers looking at an aquatic herbicide rather than a product listed only for algae or terrestrial weeds.

The listed target range includes water lilies, cattails, and Eurasian watermilfoil, so one product may address several kinds of unwanted aquatic growth. Its spray form provides a way to apply it to selected plants, while the product information says it is formulated for use around people, pets, and wildlife, with restrictions applying to irrigation and potable water. The supplied directions are only partial, so follow the product label for application and water-use requirements.

Skip it if you need a complete application rate from the supplied product details; they provide only partial directions and note water-use restrictions.

For pond owners tackling water lilies along with cattails or other listed aquatic plants, CattPlex Pro offers a relevant target range. Check the full label before use, particularly for irrigation or potable-water applications.

Listed on Amazon as: CattPlex Pro – Aquatic Herbicide – Kills Cattails, Water Lilies, Grasses & More – Quart (32 Ounces)

#2 · Best Systemic Option

2. Airmax Wipeout Pond Weed Defense

• Weight: 4.16 oz
• Form: Liquid

Best for: Season-long whole-pond treatment.

Why it ranks #2: It explicitly controls water lilies with systemic fluridone for whole-water treatment; the listed application uses 3.8 fluid ounces mixed with water.

Systemic fluridone treatment gives Wipeout a whole-water-body approach to floating and submerged pond weeds, including water lilies and duckweed. Its slow action reduces chlorophyll rather than causing rapid oxygen depletion, a useful distinction for pond owners seeking gradual control instead of a fast knockdown.

The liquid treatment is mixed with water and applied in several spots from the shoreline, so the listed method does not require applying only to individual plants. Wipeout controls water lilies, duckweed, coontail, and other named weeds by reducing chlorophyll and starving plants of nutrients. The product information describes all-season control and says its slow action avoids rapid oxygen depletion; the directions and shipping restrictions still warrant checking before planning treatment.

Skip it if you need a product that can ship to AK, CA, CT, DC, HI, ME, NJ, NY, PR, VT, WA, RI, or Canada; this listing excludes those destinations.

Wipeout fits pond owners seeking gradual, whole-water treatment for floating and submerged weeds such as lilies and duckweed. Its shoreline application method is useful, but shipping restrictions and the label’s directions matter before purchase.

Listed on Amazon as: Airmax Wipeout Pond Weed Defense Herbicide & Aquatic Weed Control, 4 Ounce

#3 · Best Granular Formula

3. Atticus Semera 51.0% WDG

• Weight: 16 oz
• Form: Water-Dispersible Granule

Best for: Fast contact aquatic control.

Why it ranks #3: Its 51% flumioxazin formula controls selected floating, submerged, and emergent weeds, though the verified target list does not name water lilies.

Semera 51.0% WDG uses flumioxazin in a water-dispersible granule for fast contact control of selected floating, submerged, and emergent weeds. Its listed targets include duckweed, coontail, hydrilla, pondweed, and watermilfoil, making it a broad aquatic option for early or existing growth.

The product information says Semera controls weeds up to two inches in height and provides six-month weed control, connecting early treatment with continued control of new growth. Its water-dispersible granule format requires preparation for aquatic application, while the listed target range covers several plant types and locations in the water. Buyers should identify the target weed and follow the label’s preparation and application directions; the listing excludes sales to Alaska, Hawaii, Connecticut, and New York.

Skip it if you are in Alaska, Hawaii, Connecticut, or New York; this product is listed as unavailable for sale in those states.

Semera suits buyers seeking fast contact control across listed aquatic weed types, including duckweed and watermilfoil, with stated six-month control. Confirm the target and label directions, and note its four-state sales restriction.

Listed on Amazon as: Atticus Semera 51.0% WDG Aquatic Herbicide (1 lb) – Flumioxazin Weed Killer

#4 · Best Contact Action

4. Pond2O Diquat Herbicide

• Weight: 1.8 lb
• Form: Liquid

Best for: Rapid contact pond treatment.

Why it ranks #4: The 32-ounce liquid is described as fast-acting against floating mats and submerged growth; its supplied target information does not specifically name water lilies.

Diquat’s rapid contact action is the central feature of Pond2O, which is described as scorching floating mats and submerged growth for quicker pond restoration. The listing gives a treatment mix for 10,000 square feet, helping buyers connect product quantity with a stated surface area.

The stated mix is one quart with 25 gallons of water plus eight ounces of Surf for 10,000 square feet, giving users a specific preparation and coverage reference. Pond2O is described as penetrating tough foliage and acting rapidly on floating mats and submerged growth, with intended benefits including clearer water, circulation, and access for fishing or irrigation. The listing describes it as safe for fish when used correctly, so label directions govern application.

Skip it if you want a ready-to-use product without a mixing step; SePRO Sonar RTU is listed as requiring no mixing or spray equipment.

Pond2O suits pond owners seeking rapid contact treatment for floating mats and submerged growth, with a stated mix for a defined surface area. It requires dilution and Surf, so follow the label for preparation and fish-safe use.

Listed on Amazon as: Pond2O Diquat Herbicide, 32oz

#5

5. Applied Biochemists Weedtrine D

• Weight: 4.54 g
• Form: Spray

Best for: Broad-spectrum spray application.

Why it ranks #5: This diquat spray controls floating, submerged, and emergent weeds, including duckweed, but supplied facts do not confirm water lily control.

Weedtrine D is a fast-acting aquatic spray listed for submersed, floating, and emergent weeds, including duckweed. Its gallon-size presentation and hand-held sprayer application suit pond managers treating multiple weed types who want a liquid product applied after dilution.

The supplied application information says to dilute the product and apply it with a small hand-held sprayer according to label directions, a workflow that gives users a practical approach for targeted pond areas. Weedtrine D’s listed coverage spans submerged, floating, and emergent growth, including duckweed. The safety information calls for a surfactant when necessary for weeds on or above the water surface and notes restrictions for irrigation, drinking, and other water uses after application.

Skip it if you need water available for irrigation or drinking immediately after treatment; the listed safety information specifies restrictions for those uses.

Weedtrine D fits pond owners treating several growth types who can dilute and apply with a hand-held sprayer. Its broad listed coverage includes duckweed, but water-use restrictions and label directions are important planning considerations.

Listed on Amazon as: Weedtrine D Aquatic Herbicide 1 Gallon Spray for Fast, Broad-Spectrum Control of Duckweed, Floating, Submersed & Emergent Weeds, Professional-Grade, Easy to Use, Diquat Active

#6 · Easiest Application

6. SePRO Sonar RTU

• Weight: 2.2 lb
• Form: Liquid

Best for: No-mix residential pond use.

Why it ranks #6: The ready-to-use liquid needs no mixing or spray equipment and is intended for season-long systemic weed control, but verified details emphasize duckweed rather than lilies.

Ready-to-use liquid means Sonar RTU can be poured directly into the pond at the stated dose, with no mixing, spray equipment, or boat needed. That straightforward workflow suits do-it-yourself pond owners targeting duckweed and other listed weeds while seeking season-long systemic control.

The stated dose is four quarts per half acre at an average depth of four to six feet, giving buyers a concrete starting point for estimating pond treatment needs. Because the formulation is ready to use, there is no mixing step or spray equipment to assemble. The listing identifies duckweed and describes season-long treatment, while also specifying no swimming, fishing, boating, or livestock restrictions immediately after application; check irrigation precautions on the label.

Skip it if you need shipment to AK, CT, HI, ME, NJ, NY, WA, or Canada; this product excludes those destinations.

Sonar RTU suits do-it-yourself owners who value direct pond dosing and want a season-long option for duckweed and other listed weeds. Its specified dose assumes a particular depth range, and irrigation precautions still require label attention.

Listed on Amazon as: Sonar RTU (Ready-to-Use) Aquatic Herbicide 1 Quart, Systemic Weed Control for Duckweed and More – No Mixing or Equipment Needed – EPA Approved, Season-Long Treatment, Safe for Fish & Wildlife

#7

7. UPL Hydrothol Aquatic Herbicide

• Weight: 20 lb
• Form: Granule

Best for: Granular active-growth treatment.

Why it ranks #7: The 20-pound granular endothall product targets aquatic nuisances, but its supplied target details do not establish water lily control.

Hydrothol 191 comes as a 20-pound granular aquatic herbicide with 11.2% mono salt of endothall, a format suited to buyers planning treatment around actively growing weeds or algae. The listing emphasizes a range of aquatic nuisances, while noting that susceptibility can vary with algae strains and conditions.

The granular form gives pond managers a solid product to apply at listed rates ranging from 3 to 270 pounds per acre-foot, with the appropriate rate depending on the treatment. The product information specifically advises application when weeds and algae are actively growing, making timing part of the treatment workflow. It is presented for varied aquatic nuisances, but algae response may differ by subspecies, strain, and environmental conditions, so the label should guide use.

Skip it if you want a product explicitly listing water lilies as a target; Hydrothol’s supplied description does not name lilies among its targets.

Hydrothol suits experienced pond managers planning granular aquatic treatment during active growth and able to work from label rates. Its listed facts do not specifically identify water lilies, so match the target plant before choosing it.

Listed on Amazon as: Hydrothol Aquatic Herbicide 20# Bag- Endothol 11%

#8

8. Agrisel Diquat Weed Killer

• Weight: 2 lb
• Form: Liquid

Best for: Large-format liquid diquat.

Why it ranks #8: This 128-ounce liquid is identified as a diquat weed killer, but supplied specifications do not name water lilies or give a target-weed list.

A 128-ounce liquid format is the key practical feature of Agrisel Diquat Weed Killer, giving buyers a larger container of diquat herbicide for pond weed control. The title also identifies it as pet safe, a relevant consideration for owners managing water near household animals.

Agrisel’s listing specifies a liquid formulation and a 128-ounce package, so it is a larger-volume option for buyers comparing product format and quantity. The product title identifies diquat as the weed-killer type and describes the product as pet safe. The supplied details do not provide a target-weed list or application directions, so buyers should consult the product label to determine whether it suits their pond’s plants and how to apply it safely.

Skip it if you need named water-lily targets and application directions in the supplied product details; consider SePRO Sonar RTU, which lists a dose and describes duckweed control.

Agrisel may suit buyers seeking a large liquid diquat container and who value the title’s pet-safe description. The supplied listing lacks target-weed and application details, so verify the label before selecting it for water lilies.

Listed on Amazon as: Agrisel Diquat Weed Killer, Pet Safe, 128 Ounces

#9

9. Alligare Flumigard Herbicide

• Weight: 5 lb
• Form: Granule

Best for: Granular algae and weed control.

Why it ranks #9: Its 5-pound flumioxazin granules are described for algae and young terrestrial weeds, not specifically for water lilies in the supplied details.

Flumigard combines flumioxazin granules with claims of rapid knockdown for filamentous algae and young terrestrial weeds, including in aquatic settings. Its five-pound container and surface or subsurface treatment directions suit buyers addressing algae or young weeds across listed aquatic, forestry, and bare-ground sites.

The granules are described for pre-emergent and post-emergent control of young weeds, giving buyers a use window that covers both prevention and early growth. The listing also identifies filamentous algae and calls for surface and subsurface treatments, while specifying 6 to 12 ounces per surface acre when mixing with other herbicides. Required safety gear includes long sleeves, long pants, waterproof gloves, and proper footwear, so treatment planning includes protective equipment.

Skip it if you need a product explicitly listing water lilies as a target; Flumigard’s supplied targets focus on filamentous algae and young weeds.

Flumigard fits buyers treating filamentous algae or young weeds across aquatic and other listed sites, especially when considering pre- and post-emergent use. Its supplied rate is tied to mixing with other herbicides, and protective gear is specified.

Listed on Amazon as: ALLIGARE Flumigard Herbicide – Fast-Acting Flumioxazin Weed Killer for Rapid Control of Aquatic Algae and Terrestrial Weeds in Forestry, Aquatic, and Bare-Ground Sites – Granules -5lb

#10

10. Airmax Shoreline Defense

• Weight: 2 lb
• Form: Liquid

Best for: Emergent shoreline weed control.

Why it ranks #10: It is aimed at emergent shoreline weeds such as cattails, grasses, and brush, so it is a poor fit for floating lily pads.

Root-targeting control of emergent weeds makes Shoreline Defense a fit for reclaiming a beach, dock edge, or pond shoreline rather than treating only floating growth. The liquid herbicide lists cattails, phragmites, grasses, weeds, and brush, and can be used in fresh or brackish water.

The product targets roots of persistent emergent weeds, which supports shoreline cleanup where regrowth from established plants is a concern. Its liquid form is mixed for application, and the listing recommends adding a surfactant for best results. With target examples including cattails, phragmites, grasses, and brush, it suits vegetation at the water’s edge; the product information says there are no water-use restrictions and that label-directed use will not harm listed animals.

Skip it if you need a product explicitly listing floating water lilies as a target; Shoreline Defense is presented for emergent weeds, grasses, and brush.

Shoreline Defense suits owners reclaiming a beach, dock edge, or overgrown pond margin where emergent plants are the issue. It is not the specifically listed water-lily option, and the label should guide mixing and application.

Listed on Amazon as: Airmax Shoreline Defense Emergent Weed Control Herbicide, 1 Quart