# Gnatrol



## abax (Apr 2, 2016)

I'm getting conflicting advice on using this product. A reviewer maintains that distilled water must be mixed with the granules, however, the package says nothing whatsoever
about the necessity of distilled water. The reviewer said something to the effect that the
chlorine in tap water renders the biologics useless. Anybody familiar with this product and
its use?


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## cnycharles (Apr 2, 2016)

I looked at the label. It says not to mix with fungicides or others with concentrated copper or chlorine, but that chlorine in potable water supplies shouldn't interfere


Elmer Nj


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## naoki (Apr 3, 2016)

Interesting, I thought that the bacteria spores would be somewhat damaged by chlorine, but I found the direction which Charles is referring to here. It is a bit surprising to me. This paper, related to anthrax, seems to show that chlorine influences spores of Bacillus thuringiensis ssp. israelensis (="Bt", the main component of Gnatrol), but the concentration of Chlorine in the drinking water might be lower or the strain in Gnatrol is more resistant.
http://aem.asm.org/content/71/9/5587.full


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## Lanmark (Apr 3, 2016)

I use RO water when I mix it up to avoid any potential weakening of the product from tap water chlorination. I don't need to make that much of it at a time, however, and I might just use tap water if I had to make a barrel full of the stuff. "Life, uh, finds a way"


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## cnycharles (Apr 3, 2016)

I'm sure it's better to use as clean water as possible. That said anytime I've used any bt product at work I'd never had anyone mention to me to not use chlorinated tap water, hope the product wasn't killed. 

One note is not all chlorine in water is the same; different munis use different amounts according to need, and some use chloramine which I'm not sure how that reacts. Utica ny city water used the bare minimum because their water was very clean. 

Running water through a carbon filter can also knock down the chlorine level, and Charley's greenhouse supply in the nw us sells a 'chlorgone' filter with garden hose attachments for just that purpose 


Elmer Nj


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## SlipperFan (Apr 3, 2016)

I don't know about the chlorine part, but I used to use Gnatrol on my house plants with good results. However, it needs soil to hold it. Because of that, I found it not to be effective with orchids.


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## Ray (Apr 4, 2016)

Mosquito Dunks contain BTi, and are intended for use in ponds. Most folks that I know keep them in jugs of water, then pour that through the pots, then refill.


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## abax (Apr 4, 2016)

I decided to use distilled water since I had seven gallons
for my spot shot. I need to do it again two more times
at one week intervals. I think I'll just use rain water for
the next two drenchings.

Dot, I suspect Gnatrol probably isn't effective in bark, but
I hope it works on sphagnum and potting soil. That's the
source of the gnats that I see on the yellow sticky things
all over my greenhouse...primarily around my mounts
with sphagnum. It's interesting that I also mount occasionally using loose fibered coco and never see any
gnats around those mounts. I wonder if there's something about the coco fiber that gnats don't like.


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