Hello everybody!
My name is Dylan and it's a pleasure to be here. I'm part of a mechanical engineering senior design team at UCF in Orlando FL. Our task is to design and build an aquatic weed removal system. Our intention is to have a product that is useful for small lakes that can easily be used by a homeowner for instance to maintain vegetation. We know from bulrushes to hydrilla there are a wide variety of weeds to take care of especially in this area. I have spent years going at these with a rake and an old ten horse Johnson myself but I know there are more effective ways about this. I'm hoping to you guys would have some input on devices that you're already using to manage aquatic plants. I'd like to know...

What devices are you currently using?

Are there any complaints you have about these devices?

Is there anything you would like to specifically see in a new product?

Everyone's input on this is appreciated greatly!

Cutting the weeds is relatively easy (underwater weeds). Removing the weeds from the body of water will be the trick, and the supporting equipment needed to do that.

Underwater sickle mower https://www.lakemower.com/store/jenson-lake-mower-hd5000

Some weeds will reproduce from any fragments that are left in the water, so you have to know what weeds you can or cannot cut.........

https://aquaticweedharvester.com/about-us/

https://lakeweedharvester.com/eco-harvester/

I appreciate it! I've definitely had my eye on the lake mower but I agree the issue seems to be with collection. Hydrilla and milfoil can be hell to get rid of due to fragmentation. So you think my focus should be on collection?

Maybe start by defining weed removal. Like esshup said, "mowing" the weeds can be simple, removing them will be the tough part. Are you looking to build a system that will need to be used on a regular basis (giving the weeds a haircut, with full intention of them growing back), or looking to completely eradicate/uproot/kill off the weeds? I'm guessing the former, and not the latter.

somehow cutting the weeds and putting on a large boat would be nice.

I agree that collection is the biggest problem for my pond. Manually cutting the weeds with a weed razor is not nearly as difficult as getting in a boat and collecting all of the heavy weeds and bringing them to the shore.

One way we do this without a boat is by attaching a lightweight plastic garden rake to a rope and dragging the weeds in by casting out the rake and pulling it back with the rope. This is done after the weeds are cut and are floating. I think this might be a consideration for your project. A small boat that can drag the weeds instead of loading them might work. This does require the weeds to float and not break up too much though, which is why we use the technique with curly leaf pondweed.

What about an auger-like mechanism that cuts the weeds and pulls them to shore at the same time? Or, what about a weed vacuum? Remember the old Flowbee commercials? That vacuum thing that cut your hair and pulled all the clippings into some kind of receptacle? Man, I'm starting to have fun with this...

The thing about weeds is that there is a lot of nutrients tied up in the weeds. Once the weeds are cut and removed, they have to be removed from the pond/lake far enough so when they decompose rain doesn't wash the nutrients back into the pond.

We fished in a pond in southern Texas that got choked with water hyacinths. As floating plants they were relatively easy to gather & dispose of on shore. Three friends and I spent most of a day collecting them and cleared a pretty good area.

After we finished, the bass went crazy eating the stuff that had sheltered in the weeds. When we came back two weeks later, you'd never know we did a thing, hyacinths covered entire cleared area.

I have used some of these devices and have always found replacement parts to be hard to come by. However, I have ordered some parts from NES-IPS such as o-rings and they have made a real difference.

Most ponds are a closed system, and nutrients build up over time in the pond. Excess nutrients create unwanted weed growth and unwanted algal blooms, and if the conditions are right, the excess nutrients can create toxic algal blooms.

I would think available power in the equation is important, but a style of trash pump that would have a:
1. Powered cutting head on the intake to cut the plants fine enough to be pumped.
2. Mechanical articulated head of some kind. Much like an optical endoscope.
3. Potentially a camera on the head, but unlikely visibility would be any good during operation.
4. Water would vacuum up the cut plants though the pump.
5. Follow on filter/centrifuge to pull most water out after pump.
6. Further mulch the remainder for collection, drying, and disposal/mulching for gardens, etc.

Tracking where the head has been already to "mow" would be hard, as well as designing a head that didn't clog but tough enough to chew through sticks and other debris.