Is Carmax an Herbicide? Will using Carmax harm the fish in the pond? Find out what the experts at Purina Mills think about using Carmax in your pond.

Connie, from Illinois as well. Hi Connie.

Hi, there. I’m from south central Illinois, and I’d like to compliment you on your program.

Oh, thank you.

I have a two-acre pond, and we’ve had an algae problem, some of that green stuff that the gentlemen talked about looking like cornmeal. We were told to buy a product called Carmax, I believe is what it was, but my question is, is that considered an herbicide? Will it hurt the quality of the fish that we have?

Their lips will never get chapped.

I would love to tackle this one.

Go right ahead.

Carmax is probably one of the most used and, let me tell you, abused herbicides in water. First of all, it’s illegal, let’s get that straight right off the bat. You’re not supposed to use it. It’s not labeled for use in water, it’s not selective, in water temperatures of seventy degrees or more you can kill your fish.


Now, it’ll sure wipe out that algae, but it’ll take a lot of other things with it.


So it’s not a product that I ever recommend, ever. In fact, I do my best to… don’t use it!

That’s the bottom line. Wait, if it’s illegal to use in water, where is it used, if you’re not going to use it in water?

It’s used in row crops. I believe corn is one of the things on the label.

Okay, alright, so it’s other agricultural applications.

Other agricultural uses where just a long time ago in the 60s and 70s, it was recommended for use in water, and people would use it in water, but they didn’t know it wasn’t, I mean, I saw one man kill a bunch of pecan trees around the edge of his pond by using that stuff. It’s just, it’s not a good product for use in water.