SKU: 94435684581
granular pond herbicide

granular pond herbicide Hydrothol Granular Aquatic Algaecide & Herbicide

Sale price$20.47 Regular price$22.74
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 15 - Jul 20

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

granular pond herbicide Hydrothol Granular Aquatic Algaecide & HerbicideHydrothol Granular Aquatic Algaecide & Herbicide Control pond algae and submerged aquatic weeds with Hydrothol Granular 20 lb, an endothall based algaecide for lakes, ponds, canals and shoreline treatments. Hydrothol Granular 20 lb is a professional strength aquatic algaecide and herbicide designed to control nuisance algae and selected submerged aquatic weeds in ponds, lakes, drainage canals and other quiescent, slow moving or flowing aquatic sites.

Hydrothol Granular Aquatic Algaecide & Herbicide

Control pond algae and submerged aquatic weeds with Hydrothol Granular 20 lb, an endothall-based algaecide for lakes, ponds, canals and shoreline treatments.

Hydrothol Granular 20 lb is a professional-strength aquatic algaecide and herbicide designed to control nuisance algae and selected submerged aquatic weeds in ponds, lakes, drainage canals and other quiescent, slow-moving or flowing aquatic sites. Its active ingredient is 11.2% mono(N,N-dimethylalkylamine) salt of endothall, equivalent to 5% endothall acid, and the product is registered under EPA Reg. No. 70506-174.

Built for fast, targeted control, Hydrothol Granular is commonly used for pond algae control, lake weed control, shoreline treatments, dock areas, swim-access lanes, irrigation paths and drainage systems where the product is registered and label directions allow use. UPL describes Hydrothol Granular as a product that controls both weeds and algae, works quickly, and is primarily used at 0.05–0.3 ppm for broad-spectrum algae control, including planktonic, filamentous and branched algae.

Hydrothol Granular is especially useful when algae or weeds are actively growing. It can help manage problem species such as chara, filamentous algae, coontail, hydrilla, milfoil, naiad, elodea, pondweeds and water stargrass, depending on label-permitted use, treatment rate, water conditions and local regulations. The label notes that algae susceptibility may vary by subspecies, strain and environmental conditions, so accurate plant identification and proper rate selection are important.

Algae blooms are more than a cosmetic issue. EPA explains that excessive algae growth can consume oxygen, block sunlight and make aquatic life survival difficult when algae die and decompose; WHOI also notes that many fish kills are linked to low-oxygen or no-oxygen conditions created by blooms.

Key Benefits

Benefit Why It Matters
Controls algae and aquatic weeds Targets planktonic, filamentous and branched algae, plus many submerged weed species.
Granular contact formula Easy to distribute over shoreline, spot and marginal treatment areas.
Works in still and moving water Labeled for quiescent, slow-moving and flowing aquatic sites.
Useful for targeted access areas Helps clear dock, shoreline, swim-lane, irrigation and drainage access zones when used according to the label.
Endothall-based chemistry EPA’s archived technical fact sheet reports that endothall is not expected to adsorb strongly to suspended solids or sediments in water and is not expected to bioaccumulate in aquatic organisms.

Best Uses

Application Area Common Targets
Ponds and small lakes Filamentous algae, chara, coontail, milfoil, hydrilla, naiads, pondweeds
Lake shorelines and docks Submerged weeds and bottom-growing algae around access areas
Drainage canals Algae mats and aquatic vegetation that restrict water movement
Irrigation systems Labeled aquatic weed and algae control where permitted
Spot and sectional treatments Marginal areas, boat lanes and limited-use zones

Label-Based Application Rate Summary

Always follow the current product label. Rates vary by target species, water depth, infestation level, water movement, and treatment objective.

Treatment Target Endothall Acid Rate Hydrothol Granular Rate Notes
Light to moderate planktonic or filamentous algae 0.05–0.3 ppm 3–16 lb per acre-foot Repeat only when algae reappear and reach treatment levels.
Branched algae / difficult algae Up to 3.0 ppm Up to 162 lb per acre-foot Applications above 0.3 ppm are suggested for commercial applicators as marginal or sectional treatments due to fish-toxicity concerns.
Submerged aquatic plants 0.5–5.0 ppm 27–270 lb per acre-foot Professional application is recommended, especially for larger or higher-rate treatments.
Ponds/small lakes with little to no outflow — planktonic & filamentous algae 0.25 ppm 15 lb per acre-foot Label example for small lakes/ponds.
Ponds/small lakes with little to no outflow — branched algae & aquatic plants 0.5 ppm 30 lb per acre-foot Label example for small lakes/ponds.

 

Quick Rate Chart

Rate Pounds per Acre-Foot Ounces per 1,000 sq. ft. per Foot of Depth
0.05 ppm 3 lb 1.0 oz
0.1 ppm 5 lb 1.9 oz
0.3 ppm 16 lb 5.8 oz
0.5 ppm 27 lb 10 oz
1.0 ppm 54 lb 20 oz
2.0 ppm 108 lb 40 oz
3.0 ppm 162 lb 60 oz
5.0 ppm 270 lb 100 oz

 

Important Safety & Use Restrictions

Topic Label-Based Guidance
Read the label first It is a violation of federal law to use this product in a manner inconsistent with its labeling.
Fish and aquatic life The label states this pesticide is highly toxic to fish and aquatic invertebrates, and fish may be killed by dosages above 0.3 ppm. Dense algae or plant growth should be treated in sections to reduce oxygen-loss risk from decomposing vegetation.
Professional application For higher-rate algae applications and submerged plant control, commercial applicators are recommended for marginal or sectional treatments.
Do not use in certain ponds Do not use in waters containing Koi or hybrid goldfish. The product is not intended for small-volume garden pond systems.
Water type Do not use in brackish or salt water.
Potable water Consult state or local water authorities before applying to public waters. The label includes a 600-foot setback from functioning potable-water intakes in lakes, ponds and other quiescent water bodies.
Treatment size Do not treat more than 10% of the area at one time with doses above 1 ppm.
PPE Mixers, loaders, applicators and handlers must wear label-required protective clothing, gloves, protective eyewear and approved respiratory protection unless a label exception applies.

 

Shipping Restrictions

Restricted Shipping States for This Listing
CA, CT, NJ, NY, WA, OR, ME


FAQ

What does Hydrothol Granular control?

Hydrothol Granular controls a broad range of algae, including planktonic, filamentous and branched algae, and it is also labeled for selected submerged aquatic plants such as hydrilla, coontail, milfoil, naiad, elodea and pondweed species.

When should Hydrothol Granular be applied?

Apply when target algae and aquatic plants are present and actively growing. For ponds and small lakes with little to no outflow, the label recommends early-spring applications when weeds are actively growing and a minimum 24-hour contact time can be achieved.

Is Hydrothol Granular safe for fish?

Hydrothol Granular must be used carefully around fish. The label warns that it is highly toxic to fish and aquatic invertebrates and that fish may be killed at dosages above 0.3 ppm. Treat heavy growth in sections and use qualified commercial applicators for higher-rate or large-scale treatments.

Can Hydrothol Granular be used in muddy or murky water?

Endothall is reported by EPA’s archived technical factsheet as not expected to adsorb to suspended solids or sediments in water, which supports its usefulness in murky conditions when label directions are followed.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 94435684581

Discover Niche Categories That Outsell granular pond herbicide

Top-Converting Item to Boost Your Average Order

4.2 ★★★★★
Based on 969 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
R
Verified Purchase
Rose Cottingham
Waukegan, US
★★★★★ 5
This mattress cover is great! Well worth your money
Size: Twin XL, Style: 1 Green
This mattress cover is so comfortable. I am scheduled for back surgery in a week so when I find something I can sleep on and call it comfortable you best believe it is! It fits well, it’s pretty and it’s very fluffy. Seems to be made very well. I am confident that I’ll get a lot of wear out of it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2026
T
Verified Purchase
Tiffany F.
Natrona Heights, US
★★★★★ 5
Very Comfortable - Love this!
Size: Full, Style: 1 Green
So far, so good! I am going on my first night trying this mattress topper out. It feels very comfortable and definitely is fluffy, but not too fluffy. I did not "fluff it out" or put it in the dryer to fluff it out quicker, so perhaps it still needs some time to fluff out some more. It was very easy to place on my mattress. I didn't have to fight with it as I normally would when fitting a sheet to my mattress. I love that it stretches over the sides of the mattress to hold it in place. The bamboo truly gives a cooler effect, which will be very helpful in the summer time. I used a microfiber mattress topper prior to ordering this topper. So far, the comparison is that this one appears to be well made and durable, unlike the microfiber one I had before that changes color as it gets old and dirty and is impossible to clean. The old one actually ripped and would constantly move. I am excited to see how well this one holds up over time. I had no trouble placing a fitted sheet over this mattress topper. I love that this one is machine washable and is able to be placed in the drier. It feels very nice on my legs and is comfortable for my back as well. The padding doesn't feel thick or bulky but definitely adds a softness that is super comfortable. It's too soon to tell if it's water resistant as I haven't tested that feature out yet. I placed it over an old, springy mattress and it truly feels like I have a whole new mattress. Time will tell how well this product does the job and I will update this review if I end up having any issues with it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 25, 2026
P
Verified Purchase
PRIVATE
Port Orchard, US
★★★★★ 5
IT'S LIKE SLEEPING ON A CLOUD!!
Size: King, Style: 3 White
OMG I AM SLEEPING ON A CLOUD!!! THIS! Life changing!!! We went on a Royal cruise and asked for a mattress topper. When we got home I just had to find one for our bed because I sometimes find it to be too hard. Along comes THIS topper! The very first night it was on the bed I slept the entire night without tossing / turning which I NEVER do! Along with every night since! It fits perfectly on our King bed and no issues with the sheets. It does have a chemical smell when you first open the bag - but I put it in the dryer on air only and the smell dissipated in about 20 minutes. No smell at all by the time we went to bed. it appears to be washable. It's very soft so there isn't really any back support. Just adds comfort to the bed. It is bamboo and really as soft as a cloud! Even my husband got into bed the first night and said AHHHHHHH SOFFT! Super bright white appearance. Not sure if it is water resistant. We added it on top of the mattress protector without any issues. All of the FOAM mattress toppers are terrible! They end up getting really heavy, you can't wash them, they get lumpy, and you end up sweating like crazy on them! THIS - nice and cool! And my hubby runs hot!! I call him the heat miser! No issues! We're both very very pleased!! If you're even thinking about purchasing - ADD IT TO YOUR CART NOW!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 22, 2026
K
Verified Purchase
Kathleen Kowalski
San Leandro, US
★★★★★ 4
Not like the pictures but well worth the money
Size: Queen, Style: 1 Green
4 stars because it is not nearly as padded as the descriptions and images make it seem. The filling flattens easily and doesn’t provide any support. That being said it does make my bed more comfortable and soft and has improved my sleep quality. I have a 12 in soft/medium firm memory foam mattress that was wonderful for the last +2 years till my back surgery ~6 months ago. Since then my joints ached when trying to sleep and when waking, my back would be all out of place and achey, and I was untested. Since buying this topper these issues have improved by 80% or more. It is a great addition to my bed and I don’t regret buying it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 18, 2026
A
Verified Purchase
Aurihazuma
Lexington, US
★★★★★ 5
OMGAAAAAWD!!! HEAVEN!
Size: Full, Style: 1 Green, Size: Full, Style: 1 Green
All I can say is OMGAWD!!! Thank You~!~!! We got a new mattress after the previous "The Cloud" Serta pillow top (I'll never have another one) lasted for less than 8 years and I totally despised not being able to flip it models failed.. The new model is also a hybrid mattress, but is flippable and was just a bit too firm. I was feeling progressively more and more uncomfortable as the nights wore on, and with my serious back problems.. this just wouldn't do.. So I began searching "Our Beloved Amazon - heh" for an alternative, and after quite some time and research finally landed on this wonderful topper. It's like sleeping on top of well stuffed Ida Down on top of piles of silk. So very comfortable and my back pain is virtually completely gone now -such a relief! Be sure you follow the instructions on care and initial setup. You Do have to let it fluff out because of the vacuum packing (it wasn't really heavy btw). Mine decompacted fine, but I still want to run it through the dryer when we next venture to the laundromat. Shake it a little here and there when you take it out and at least let it sit for a few hours. It was just as easy to put on the bed as a regular mattress protector, and I also put my regular protector on top of it for added security and waterproofing. The materials feel like they are of good quality.. Viscose is also called Rayon and can be made from a number of different materials, so take good care of it and follow the washing instructions carefully. Delicate only, and cool only, and use only a horizontal washer that does not have a central agitator or you will tear it up. Only dry on low temperatures (preferably in a very larger laundromat dryer so it has plenty of room to loosely toss about. Drying it in the sun is alright as well, but it won't fluff like you want it to. I recommend using a waterproof and bug proof protector on top of this just to be sure you take care of it properly. Now I want to buy one for both my Mother and my Aunt HAHAHHA! TG it is in my price range.. barely. (Addendum: I have run it through the big dryer at the laundromat.. The dryer was cold so I gave it a quick warm on medium for anout 2 minutes and then tumbled on low for quite some time. The topper was fully ready in about 25 minutes, but I decided to elt it go on low while I did the rest of my laundry. It did perfectly and is just like the manufacturer photos.. I was so tired when I arrived home that I just flaked out on top of everything.. It was so comfortable that I was out liek a light in very short order and slept beautifully. I can attest that if you use this below your sheets instead of covering it with an additional mattress protector, that it does have better cooling effect. I will of course keep my waterproof/bugproof protector on top just for safety. The cat is nutz about the new topper as well.) Namaste.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 6, 2025

recommand products