Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Controlling weeds in a trout pond

I know that trout are sensitive to copper based herbicides. Are they also sensitive to other herbicides? I have both chara, and a species of pond grass along with some cattails growing in my trout pond. Can I use the typical emergent herbicide for the cattails, and is there a safe herbicide for the others, although chara is not too bad of a problem as it stays on the bottom. The pond weed species I have comes all the way up from the bottom at 9 feet, and it makes fishing very annoying.

Cecil - I've ignored your post due to my ignorance of trout (a double-negative?). In any case, glyphosate "should" be safe for treating cattails in a trout pond - if necessary. BUT, you'd best check with local herbicide/fisheries specialist on that matter, to be certain. Regarding the other species mentioned: chara will likely be very tough to control with an algaecide without posing a threat to your trout. You might check on the prospect of using REWARD (diquat) rather than a copper treatment. The Poto's; maybe the same product would give you some relief.
Not exactly definitive answers; just some guidance for direction. Let me know how it pans out. Good luck. Kelly

Kelly,

Thanks for the info. I will check w/ a local biologist on the glyphosate (sp?)regarding trout and the cattails.

The chara is not much of a problem as it usually stays on the bottom and keeps bottom sediment intact therefore keeping the water clearer. I have very fine clay in the pond which is easily kicked up by even trout so anything that stabilizes it is welcome. It's the long strands of the potomegeton species that is annoying. However I just may elect to cut it off periodically w/ my weedcutter.

Thanks again,

Cecil

Yea, use the weed cutter; it's not like you have acres and acres of waterweeds to chop. Do you have one of those rope atttached, Y cutters that cuts a 4 ft wide path? Keep it sharp. I use mine to cut "fishing holes" in the curly leaf pond weed, works pretty good in small situations like ours. Pondweed is not like chara, when cut pondweed floats and just drag it out. Harvest is key to nutrient removal and reduced algae growth in small ponds. Of course when you feed, no way, you can keep up with the nutrient accumulation.

PS When are you going to send me some of the pondweed? Too late to send this week; I will be out of town Wed to Sun Oct 27 (diatom workshop - Phila).

Bill,

Sorry things have been really hectic around here. First I was harvesting fish for sale, then treating the trout pond one more time w/ buffered alum, now I am shipping off fish.ON top of that I am also doing taxidermy.

I think I will just have to give up on clearing the water as it is now just as cloudy as it ever has been. At least it is clay and not run in silt from erosion which is worse. My trout seem to adapt but I'd rather have one less stressor!I'm starting to think it is the trout that are kicking up the clay! We've caught several right on the bottom.

I froze up a sample of the weed in a freezer bag for the time being. Is that O.K.? I will wait until you get back to send. In the meantime I will attempt to find out the scientific name the professor identified it and see if you concur.

Sounds like you are busier than a one armed wallpaper hanger.

Freezing the water weed is okay but spreading it out some and drying it between newspaper would be better. Frozen might be a little mushy when it gets here. Dry will probaly crumble in an envelope. Can't win. Storing it in the frig is probably a good thing to try. Can you get some of the fruiting structures (seeds) in the collection?

If your pond clears up after alum sulf. treatment, then returns cloudy it's the wind or inhabitants that are stirring it up; probably all those underwater motor boats with fine scales!

Bill,

I think you're right on the fish and wind being the culprits. It's just logical.

I notice when it gets really cold and the fish slow down the water clears up a little.

I did somewhat of an experiment last winter. I shut down the diffuser (suspend it this time of year to keep water open for feeding), and let the pond freeze over for about a week. The water did clear up quite a bit probably due to no wind and the fish movement had substantially slowed down.

I still hope to afford a liner if I put in another pond. I've had exellent luck with greenhouse plastic but it is not made large enough. I've purchased 100 buy 40 foot pieces for my holding pond. Talk about gin clear water after the iron has settled. It's breathtaking!