I Treated the area around my dock with HYDROTHOL 191 granular this weekend.

My question is this:

How long does hydrothol take to kill the vegetation (bushy pond weed and skunk weed)?

Also how long will this product remain active in the lake?

One last question - after treatment, how long does it take for the vegetation to fully decompose (time it takes for the total effects of the hydrothol to finish)?

The reason for my questions is:

If the product works well for my problem, I would like to treat other areas of the lake but I dont want to be to aggressive in my application of the product.

Your input would be appreciated.

Don Stuart

Don,
Hydrothol is a good choice for algaes, especially chara, or "skunkweed". But, check the label. As I recall, it doesn't work well on pondweeds. Read the label for "naiad" or "potomogeton". And, I haven't used hydrothol in years. When did you acquire your bucket of it?
Secondly, the product stays "active" for several hours, that's it. It breaks down into harmless salts in a short while.
Expect the plants to die within hours of receiving the proper dose, but you might not see the difference until 5 or 6 days after treatment this time of year.
Your key here? Be sure the herbicide works for plants you want to be rid of. Double check the label, and be sure plants are identified properly.

Don,
Agree with all that Bob said and will add this: Aquathol Super K granular works very, very well on almost all of the Pondweed family(check label). Hydrothol191 is very rarely used today as there are better alternatives in most situations. I am a Certified Aquatic Applicator here in Pennsylvania and have not used Hydrothol 191 in years. Hydrothol 191 is made by the same company that makes Aquathol Super K granular.
Harry

Thanks for the info!

What would you use In the place of Hydrothol 191 Granular to treat my excess vegetation & algae (It was my understanding hydrothol treats both)?

Would you suggest I use 2 products or is there a single product that will treat both general pond weeds as well as algae.

thanks

Don

Don - I think we discuss Hydrothol and its "typical" use as an algaecide?

Hydrothol may be used as a "herbicide" at higher dosage-rates. However, it may become hazardous to your fish at such rates. Any rate over .3 ppm is consider risky to fish.

If a chemical treatment is needed, I would encourage using separate treatments for algae and plants. Hydrothol, Reward, Captain or Cutrine Plus for algae - and Aquathol, Sonar or Nautique for undesirable plants - depending upon the specie being targeted and the circumstances surrounding your situation.

Don,
I would use Aquathol Super K Granular for spot treatments on the vegetation and a copper-based liquid like Cutrine Plus for the algae. Follow label instructions always. If you have very shallow areas that produce a lot of algae and they are accessable, you can use Cutrine Plus Granular copper-based algaecide. A common hand held/cranked spreader works fine.
Harry