Ok I have hydrilla around the edges of my 1.5 acre pond. Had it pretty bad a few years ago and had someone come treat it. It is currently not thick yet but I know will be if I let it go.

Two questions - I have the ability to let my pond draw down a foot or so and then refill with my well. Is that effective for killing this weed?

Second question - I have around 10-12 grass carp that have been in the pond for 3-4 years - they are large. I am curious why they have not hit the hydrilla hard? Thanks

I won't speculate on the first question, as I have never ran into Hydrilla.
question #2: They are not eating the Hydrilla because there is something else available that is more desirable.

I have read that Hydrilla is one of the grass carp favored weeds to eat

I like ice cream but prefer some flavors over others........

I have read that smaller carp are more apt to clear vegetation than the older larger ones. It may be time to get the larger ones out and re-stock some younger ones. Here's a quote from the Misosuri conservation Dept...


"When and How to Harvest Grass Carp

There are generally two circumstances that lead to harvesting grass carp from a pond.

When nuisance plant growth becomes controlled, particularly in ponds stocked to the maximum density (20 grass carp per acre). Reduce the grass carp by about 50 percent. This prevents over grazing and eventual denuding of the pond bottom.

When the growth rate of the fish becomes slow. Since grass carp feeding habits decline around age eight and they cannot reproduce in ponds, older fish need to be removed and restocked with younger fish."


Found here...



I'm not sure why the above link looks like a YT video. Copy the following into your favorite web browser without the quotation marks...

"https://mdc.mo.gov/your-property/improve-your-property/habitat-management/pond-stream-management/ponds-plant/grass"