How to de-activate Roundup?

[Jerry in MN]

I have one of those 275- or 300-gallon plastic cube tanks with a steel cage around it. The price was right, no charge, but it had Roundup(R) in it and I'd like to use the tank for storage of rainwater for plants...when it's safe to use for that.
I asked a chemical salesman how to de-activate it. First he suggested a chemical he sells, then he seemed to suggest that soap would probably work and seemed more confident that bleach would "neutralize" it. I don't have a power washer and I'd rather not haul it into town to the car wash.
I'm thinking to use household bleach. Has anybody here done this, and did it work? How much bleach? Would I need to fill the whole tank with water too? Maybe rinse it at least three times too? Any other advice? Thanks.

[hintonlady]

We have one of those tanks. We rinsed it a few times, left it in the sun to cook, not on purpose though, then rinsed some more.

Right now we actually use it to transport water to our pasture for livestock and have for many, many months. NEVER had a problem with the stock or plants when the trough's are dumped to be cleaned.

Just clean it out and do a test watering strip in a grassy spot or somewhere not critical. After a couple waterings and a week or two if nothing looks sickly you should be fine.

[anniew]

I don't know how to "deactivate" it, but I think that it is only active for about 7 days...but that may be when exposed to sunlight and microbes.
Why not fill it and use it on some potted plants of various kinds and see if it is still "active." If they don't show any symptoms after a week, you might be okay.
They often used to tell people to clean out tanks with ammonia...that might help, but they also said to use different tanks for herbicides (Round-up) than for other pesticides, so ????
Let us know what happens.

[hintonlady]

Footnote:

I've noticed that the efficacy of roundup isn't so grand anyway. We have soy growing in our weed patches after round up, if you know what I mean.

It's not a big bad oogie boogie, scary chemical like many think.

[deaconjim]

I could be wrong, but I seem to remember that amonia is used to neutralize weed killers and pesticides in sprayers. I would check with your extension agent, or with Monsanto.

[Jerry in MN]

Good advice, to test it first. Thanks to both of you.

[cc-rider]

I may be wrong, but I thought that just plain water neutralized it! That's why you can't have rain on it within such a period of time. And I remember being told once that once it hit groundwater, it was inactive. On the label, it says that if you get it on "desirable" plants by accident, to rinse them off with water.

[DaleK]

No need to deactivate it. Just rinse it a couple of times. There won't be enough active ingredient left sticking inside the container to do anything by the time it's diluted out.

[scorpian5]

for plants it would work if you wash it good but i would never trust it for watering animals. Do not give water to livestock that you wont drink.

[Barnyard]

dh says its a salt based. says it deactivates as soon as its dry, when hits the dirt, and when too much water hits it. he was a farmer for 20 years. he says it won't harm horses if they eat grass/weeds its sprayed with. i can attest to this.

[jassytoo]

I once sprayed a whole bed of plants with roundup by mistake. I soaked the bed good with the hose and didn't lose a single plant. So I imagine if you wash the tank out well with water it would be o.k.

[rambler]

This likely held RU concentrate, not the mixed with water diluted stuff.

So, any residue would be pretty heavy dose.

Amonia is a good tank cleaner for most farm chemicals.

The farm supply store sells little bottles of tank neutralizer for your needs.

Triple rinsing, filling the whole tank all 3 times, should be good enough.

Roundup deactivates itself almost on contact with clay particles. The clay & the RU bond to each other very quickly, and then the RU breaks down in the elements fairly quickly from there. So it has no long-lasting effect once it is sprayed, only when it hits a green plant freshly sprayed does it affect the plant.

However, contained in the tank as a concentrate, it likely has not broken down much just sitting there.

Triple rinsing, or using household amonia and then rinsing out a couple times should be good.

The test strip is a great idea.

--->Paul

[Use Less]

What about a couple of gallons of vinegar OR pool chlorine as rinses? NOT both! Just be careful handling (and inhaling vapors) pool chlorine. Sue

[longrider]

Most weed killers and in particular Round Up deactivate themselves after two weeks in the ground. Which is to say they no longer stop Krebs Cycle in the plant. I RU my garden new garden sites one full month before i turn the soil. My degree was in Molecular Biology and I know enough to know that time is the key to most cleaning problems.

Soap and warm water would be my approach- lots of water, drained in an area that wont need plants for a while. I would wash and dry several times and then press on.

I would not however use this tank for any kind of potable water (drinking) system for man nor beast.

PS. as a side note: Do not handle Round Up and Triazicide or other bug killers at the same time or on the same day. Use gloves when handling either and wash aftewards- you dont want to know what the combination will do to you. *serious nerve damage*