I hate fungus gnats!

Say10

Member
As the title suggests, this post pertains to fungus gnats. God I hate them things! And they are seemingly unavoidable, unless I'm missing something.

For a brief intro, I'm no beginner at growing, however I wouldnt consider myself an expert either. Every cycle I'm constantly trying to learn new techniques to improve yields and make any neccesary changes as I see fit. I've had fungus gnats destroy a crop years ago, so I know what out of control problems can do.

Where I'm at now- before every grow, I let a can of Doctor Doom off in the room once the soil has already been mixed and in the pots for a few days, that way any bugs that might crawl out will have come out by then. I always remove all excess soil from the room as well. Now, I use approx 1/2" or so of GnatNix on top of the soil, place a couple liquid fungus gnat traps around the base of the plants, and hang a a yellow sticky tape trap next to the plants as well. Since I've made these changes, I've yet to have a gnat problem get out of control, but they're always there everytime still!

I've seen them crawling on the gnatnix on occasion, and last night had them exit from the drain holes on the pot when I watered the plant. I applied a 1:4 mixture of H2O to H2O2 to hopefully kill any eggs in there. 3/4 plants show no issues, but 1/4 never took off and is about to be removed from the room - I assume the gnats got at this plant when it was real young and stunted it.

What's the the best way to remove/battle these demons? Any tips to prevent them from entering the drain holes on the bottom of the pots? Being that GnatNix are no longer produced and I've only got a limited supply left, are they any other alternatives to this? Thanks a ton!
 

Sfrigon 1

Well-Known Member
Try and make them feel not welcome. There are like five dif things I do. High fan speed, cool nights , keep tops of soil dry, diatomaceous earth, and yellow sticky traps. I feel this is the safest way
 

Say10

Member
Try and make them feel not welcome. There are like five dif things I do. High fan speed, cool nights , keep tops of soil dry, diatomaceous earth, and yellow sticky traps. I feel this is the safest way
I do have fans going 24 hours a day - 2 fans in opposite corners of the room on rotate blowing hard enough to almost make the leaves want to curl some. With the time of year it is, nights get to around 61 or so when the lights are off. Upper 70's with lights on.

What do you do with the DE? Just occassionaly sprinkle the surface of the soil? Ive tried that in the past but no longer have been using it since I've had the gnatnix.
 

Sfrigon 1

Well-Known Member
I do have fans going 24 hours a day - 2 fans in opposite corners of the room on rotate blowing hard enough to almost make the leaves want to curl some. With the time of year it is, nights get to around 61 or so when the lights are off. Upper 70's with lights on.

What do you do with the DE? Just occassionaly sprinkle the surface of the soil? Ive tried that in the past but no longer have been using it since I've had the gnatnix.
Yeah once the tops dry I lightly dust em all maybe once a week . When u combine all these it works . For me anyways
 

Say10

Member
You can also put a small fan aimed directly at the soil. If they cant land....they cant reproduce.
I do currently have fans blowing in that area. My issue seems to be that they're getting in through the drain holes on the bottom of the pots. I've already got the barrier on the top soil surface with the gnatnix.
 

Sfrigon 1

Well-Known Member
I do currently have fans blowing in that area. My issue seems to be that they're getting in through the drain holes on the bottom of the pots.
Really never seen that or even thought it! Very interesting, learn something new everyday
 

Say10

Member
Really never seen that or even thought it! Very interesting, learn something new everyday
I've noticed it when I water the plants, and as soon as you see water come out through the drain holes, a few gnats fly out from down there. I feel like a physical barrier would be nice, but not sure how good that would work since it needs to be small enough to keep gnats out, but still large enough to allow the soil to get air and drain.

Thanks for the link and info, I'm going to head over and check it out now. This is new to me, havent heard of it/used it before.
 

Say10

Member
gnat nix.jpg
This currently what is use on the surface, GnatNix (not my photo, just one I pulled off google).

I'm trying to think of some fine mesh that I could possible use over the drain holes, or somehow rig up a secondary drain pain with the first one full of something like the gnatnix to prevent them from getting in through the bottom, and then emptying the the second drain pan of the water (similar to an ebb and flow hydro setup).

I'm probably just overthinking this and the issue isnt as bad as I think it is, but really just want to give my girls the best chance everytime for max potential.
 
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