I have an organic soil grow going with fungus gnats in the soil. and also I have them in the sealed container that I have a new batch of soil cooking for the next grow. I believe they came from the worm castings, but not 100% on that. Anyways I've come across a solution on here and other sites. It says to mix hydrogen peroxide with water and water the soil to kill them and the larve. My problem with that is, if I am using that to kill gnats won't that also kill the living ecosystem I've created in the soil? Any thoughts or feedback from some experienced organic growers would be greatly appreciated.
I need help with fungus gnats in organic soil
- Thread starter Brads420
- Start date
Conradino23
Well-Known Member
Try this: BTI For Fungus Gnats
Stop over watering and you will not get fungus gnats. Fungus gnats are caused by over watering its the only cause.
CindyLouToo
New Member
I'm new to growing mmj but have found an excellent pest deterrent...at least for the smaller soft shelled bugs. If u sprinkle diatamaceous earth (food grade) on your girls that should help immensely. I tried almost every organic spray available with disappointing results. My plants are doing great as far as being nearly bug free. Its really quite amazing stuff and totally organic.
I really like what the diatomaceous earth does to the critters. Gnats are not my friend! I keep some yellow sticky traps around for the adults and to guage their activity/population level.
hockeybry2
New Member
I second the diatomaceous earth... does wonders
To get the greatest benefit from DE it must be applied after the top layer of the soil has begun to dry some and then coat the surface with a dusting of DE. This means you need to reapply after every watering or the gnats flare up again. After application it works beautifully, but it became obvious to me that it wasn't killing off the larvae, the very things that will ultimately damage the roots of the plant.
It makes more sense to use a fan to dry out the top layer of soil. It's the moisture that allows the gnats to even be there.
That BTI looks interesting. Have you ever used it conradino23? After reading info on the BTI link you shared I now understand why they kept coming back. Very interesting.
It makes more sense to use a fan to dry out the top layer of soil. It's the moisture that allows the gnats to even be there.
That BTI looks interesting. Have you ever used it conradino23? After reading info on the BTI link you shared I now understand why they kept coming back. Very interesting.
Conradino23
Well-Known Member
Never used it, but I read a lot of good testimonies.
Dutty Panty
New Member
That is entirely incorrect. Soil can carry eggs. Kill them. There are numerous gnat nix products out there.
Dutty Panty
New Member
Moist conditions they do thrive in and lower humidity can help control the problem but overwintering don't just make them develop weirdo.
The problem is that you may kill the adults but the life cycle of the larvae mean that the next time you water they will be back with a vengeance. Once they've established in your soil they can be ridiculously difficult to eradicate without some biological assistance.
Dutty Panty
New Member
I meant over watering Damn auto correct. Here's a pic of what I use. I can guarantee it works.
Dutty Panty
New Member
What it does is water breaks the pellets down. The larvae of the gnat feeds on it and dies. No gnats boom! Sunshine soil is horrible for gnats I used to fight those bastards Everytime I transplanted then watered. Most times you get them you can thank the soil.
Dutty Panty
New Member
I randomly get them maybe twice a year if that. I always sprinkle it at the top of soil when I transplant just in case.
Dutty Panty
New Member
Gnat stix work well in conjunction with mosquito bits. I got gnats bad early this cycle from royal golds basement. Worst I've seen in years since the sunshine bale days. But they are gone now finally.
I have good expiriences with spraying a bit of a neem oil solution on the surface of the soil (indoor) once a week / every two weeks. In combination with yellow traps, i keep the 'gnats population on a very, very low level.
I also use the neem oil in veg' stage as a prophylaxis against other beasts - but be warned, it's not digestible by humans too. Got a shitty day after eating some leaves, which i sprayed weekS before.
I also use the neem oil in veg' stage as a prophylaxis against other beasts - but be warned, it's not digestible by humans too. Got a shitty day after eating some leaves, which i sprayed weekS before.
might sound daft but i remember reading something about cats flea collars lol 
... look it up, i am sure ive read some tips and this one worked 
... look it up, i am sure ive read some tips and this one worked Similar threads
