Pond Boss Forums MANAGING AN EXISTING POND Fertilization Too late to fertilize?

I've been away for work the last 6 months and I didn't get to work with my pond so now I have hydrilla growing to the surface even in the 12' deep water in my 1 acre pond. Water is as clear as a pool, hard to catch bass, only have rain run off does the water get a little dingy and I can catch them for a little while. I am in South Louisiana, still 80 degrees, and I will use chemicals to start killing off some of the hydrilla, too much habitat, fish are everywhere. Water is still 80 degrees, can I pour liquid fertilizer and expect an algae bloom this late in the year? Thank you in advance!

You won't get a bloom as long as you have the plants growing in there, the fertilizer will feed the plants.

Agree with esshup. Nuke the plants but do it by area. The dying plants will cause O2 depletion. So, do about 20% of the pond at a time. The fish can go to the other areas.

What is the best herbicide to kill hydrilla? Sonar, Weedtrine-D, or something else? I've been reading and thinking about killing the hydrilla in areas, my entire 1 acre pond is covered in hydrilla, fish everywhere, just hard to catch, they have too much cover to live in. I don't understand how I can control my area of coverage if I use a liquid herbicide, it seems easier to use a granualar one like Cutrine Plus? Thank you!

Cutrine Plus is not a herbicide, it's an algaecide.

Are you 100% sure on the ID of the plant?

https://aquaplant.tamu.edu/plant-identification/alphabetical-index/hydrilla/

If you are 100% sure on the ID:

If I was treating the pond for a customer I would use a mixture of Cutrine Plus and Galleon, making sure I applied it according to the label. READ AND FOLLOW THE LABEL DIRECTIONS Don't forget to check the alkalinity of the pond to adjust the amount of Cutrine Plus and don't forget to use an approves surfactant with the Galleon. I would treat it by subsurface injection.

For sure, it is hydrilla. I will measure the alkalinity of the water before I treat it, thank you for that tip. I don't want to kill all of the hydrilla but it has become a nusiance to fish it. I intend to do sections at a time, allowing a week between treatments to assure I don't deplete the oxygen and kill the fish.

Attempting to treat sections of a 1-acre pond is akin to letting one rip on one side of the bed and expecting the odor to remain on that side. According to my spouse, it doesn't!! ha!
Seriously, confining the impact of any herbicide based on its placement within a dynamic (constantly transitioning) environment is highly unlikely - even with granular products. Once an active ingredient is applied (whether using a granular or liquid "carrier" to distribute the active), it become mobile within the water-column and is likely to move or diffuse into untreated adjacent areas; although dilution-factors may reduce or impede its activity in said adjacent areas. Regardless, the degree of impact outside of the treated/targeted area will likely be out of one's control - and completely dependent upon several environmental factors that are present.
If you're attempting to selectively take out hydrilla while leaving other plant species intact, you'll need a much more refined tactic - and select an appropriate product. If that's not the case, you can initiate your whole-pond treatment earlier in the season (early spring), before the hydrilla's biomass has grown too large - and while water-temps are still relatively low - and still conduct an aggressive treatment that poses relatively little risk of causing a DO-crash.

Listen to what Kelly has to say. He's been in the weed treatment biz for over 30 years.

Kelly, good to see you again!!!