Diatomaceous Earth and Fungus Gnats

[Glodenglow1]

I'm using de in conjuntion wwith a few other means of controlling fungus gnats.

I typically sift later of de using a pastry sifter all over the top of the soil. I'd say I typically use about 1/4 cup of de per each 15 gallon soil container.

Am I going to run into issues with my soil mix, as each ttime I water, the de dissolves and heads down into the soil matrix?

 

[kayaN0W]

im interested to know as well. I havent had any problems with it at all.
as long as you dont get it to clumped up to where itz cloggin up things
all shud be well.....but i cud be wrong lol. But like i said, all has been well
with mine...and im gonna continue to cycle it thruout my grows.

 

[headband 707]

I'm using de in conjuntion wwith a few other means of controlling fungus gnats.

I typically sift later of de using a pastry sifter all over the top of the soil. I'd say I typically use about 1/4 cup of de per each 15 gallon soil container.

Am I going to run into issues with my soil mix, as each ttime I water, the de dissolves and heads down into the soil matrix?

Yeah this is not the greatest idea as DE it is pretty dangerous and although it will kill the adults it won't kill the eggs and you would have to keep on using it . Peace out Headband707

 

[big_daddy]

I'm using de in conjuntion wwith a few other means of controlling fungus gnats.

I typically sift later of de using a pastry sifter all over the top of the soil. I'd say I typically use about 1/4 cup of de per each 15 gallon soil container.

Am I going to run into issues with my soil mix, as each ttime I water, the de dissolves and heads down into the soil matrix?

Glodenglow,

DE is also a source of silica which is a good thing, and it is made from the combination of the skeletons of diatoms, which are tiny single celled prehistoric creatures, and a volcanic ash called [FONT=Verdana, Geneva, sans-serif]pozzolana.
[/FONT]
Pozzalona also has silicon, but it is also aluminus, so it's important to not over do it. Humic substances can "unlock" the aluminum which can be toxic to your plant/plants.

As DE doesn't do much to the larvae which are the main problem, you may also consider top dressing with neem cake to help control your fungus gnats.

HTH

b_d[FONT=Verdana, Geneva, sans-serif]
[/FONT]

 

[Glodenglow1]

big daddy,

thanks for the info on the de.

I didn't include that about a week ago I put down a top coat of neem and karanja seed meal, followed by the sifted de, and then a sliught top coat of lavendar flowers

 

[mad librettist]

if you are going to apply it, do it right. a sifter does not cut the mustard. use a proper plant duster.

 

[MrShpongle]

I tried using DE to battle the gnats for months and it never seemed to work. Once you water, the DE tends to form plaques on top of the soil, but then these crack and allow access to the soil for the little buggers. I would recommend using Bacillus thurengis, aka mosquito dunks. Far more effective than DE, yet still organic.

 

[Glodenglow1]

Thanks MrShpongle,

I'm gonna try it

 

[Xerhoss]

I would recommend using Bacillus thurengis, aka mosquito dunks.

What he said.

I crumble almost a 1/4 of a dunk on top of the substrate per 3-5 gallon container and make sure there's a floater in the rez as well (if you use one).

Definitely does the trick!

 

[EclipseFour20]

Yep...2nd that opinion; Mosquito Dunks work great as part of Fungus Gnat pesticide program. The inert ingredients are calcium sulfate and cork, so you really can not overdose your water--so don't be bashful. I have been known to crush up 2-3 for my 20 gallons of brew.

 

[echo_chamber]

I put Diatomaceous Earth in a salt/pepper shaker and sprinkle it on the top of the soil for the gnats that walk on top of the soil. I also mix it in the soil mix when i transplant at about 1-2 tablespoons per gallon. I dont know how well it works, but it sure feels better knowing i'm taking that extra step to kill those annoying gnats. I put crumbled up BT (mosquito dunks) on the top layer as well and water it in. Takes a few weeks to "activate" but kills the larvae for about a month. I re-apply til last month of flowering. Fliers get caught in sticky traps and sprayed with SNS-203 solution..

 

[Glodenglow1]

I'm on it.

Thanks to everyone for the info!

 

[HenriettaHippo]

I use DE to a certain extent in my promix. I take some promix and a handful of DE and mix it together making what I call "Death Dust". After a big top watering I will spread a thin layer on the top.
I have also used very light duty in a foliar feeding spray, maybe about a teaspoon. I keep shaking it and leave a light duty coating everywhere for any insect that happens by.

<---Suddenly wonders if it would work well in conjunction with a NEEM oil foliar spraying...?

I do wear a respirator even though I use a USDA organic/human consumption safe variety: Oh gawd DO NOT use the stuff you put in your pool filter as it has been heat treated and has an ugly warning on the bag. It is a very light duty abrasive (Ask the bugs) and moisture desiccant so inhaling it will scratch up your air passages and then dry them out.

I am certainly going to check out the skweeto dunks to use in conjunction with the DE I use: Every bail of promix comes with free gnats as far as I can tell.

 

[Montana]

putting a layer of sand on top works well too, and is also a source of silica, fungus gnats are a typical sign of overwatering.....

 

[headband 707]

Glodenglow,

DE is also a source of silica which is a good thing, and it is made from the combination of the skeletons of diatoms, which are tiny single celled prehistoric creatures, and a volcanic ash called [FONT=Verdana, Geneva, sans-serif]pozzolana.
[/FONT]
Pozzalona also has silicon, but it is also aluminus, so it's important to not over do it. Humic substances can "unlock" the aluminum which can be toxic to your plant/plants.

As DE doesn't do much to the larvae which are the main problem, you may also consider top dressing with neem cake to help control your fungus gnats.

HTH

b_d

The absorbent qualities of diatomite can result in a significant drying of the hands if handled without gloves. The flux-calcined form contains a highly crystalline form of silica, resulting in sharp edges. The sharpness of this version of the material makes it dangerous to breathe and a dust mask is recommended when working with it.
The type of hazard posed by inhalation depends on the form of the silica. Crystalline silica poses a serious inhalation hazard because it can cause silicosis. Amorphous silica can cause dusty lungs, but does not carry the same degree of risk as crystalline silica. Natural or dried diatomite generally contains very low percentages of crystalline silica. Diatomite produced for pool filters is treated with high heat (calcining) and a fluxing agent (soda ash), causing the formerly amorphous silicon dioxide to assume its crystalline form.
The crystalline silica content of the dust's particulate is regulated in the United States by the Occupational Safety and Health Administration (OSHA), and there are guidelines for the maximum amounts allowable in the product and in the air near the breathing zone of workers.[17]

 

[mad librettist]

if you are in a big hurry to lose the gnats, like you just spotted one flying out of a seed bed, tobacco tea is quick and dirty. there are definitely risks with this method but it kills the grubs instantly.

 

[mad librettist]

you guys are really over applying the stuff. try putting it in a squeeze bottle. Shake it up to agitate it, then squeeze the bottle to make little puffs of "smoke". You want a very thin layer of dust, not visible clumps which to a gnat are like snowdrifts.

 

[Glodenglow1]

ML,

That is an excellent suggestion. I was looking for a way to get that de acting on a smaller and smaller scale, and going to a sniffer bottle looks ideal.

Thanks!