Pest control concerning gnats in soil

fast.freddy · Mar 3, 2026

Vick_Vinegar said:
Hypoaspis miles are your best bet for control. They are cheap to buy if you can't get em to propagate. I always use a shovel full of yard soil in every cook from a humus loaded area which is loaded with them.

Good for a living ecosystem. They will march around your medium and eat all the gnat larvae.

I haven't had to treat for gnats for years thanks to these little guys, and I water every day from the get go.
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Always a big promoter of predatory control when it comes to gnats.

Must have hit a button accidentally..

V anyway, it sure seems like these little tiny things are just burrowing rt into the medium - and for some reason I thought I would be able to just keep all of this type of stuff outta my grow closet, ughh..
I put up a couple of sticky fly tape's and it got a whole bunch of them, but guess if I'm not killing the larvae then I'll just keep on fighting these little bastards..
I'm sorry for not quite picking up on everything, but
- will these little buggers hurt my seedlings?
- and what will kill them before they hatch or whatever these nasty things do?
It sure would be nice if I didn't have to introduce more bugs into the closet, but whatever it takes I will do!

Thank you so much -

BeefyBully · Mar 3, 2026

Hell yea !

BeefyBully · Mar 3, 2026

are you in pots? do you worry about infestation?

BeefyBully · Mar 3, 2026

that's what I use Bavaria Bassianna for. it becomes predatory fungus after eating larvae

BeefyBully · Mar 3, 2026

To the original post:
I leave you with this. "For every action there's an opposite and equal reaction" that is law my guy!

In what world does someone shoot down an idea and not provide a solution. the solution to your issue and beyond is Choice

pop bean directly in soil. recommend the AC infinity 1/4gal nursery pot, you have 5 days till germ and 5 days to plan, it will take BTI some time to activate. by then you'll have a new sprout.

meanwhile what do you use to track?

trygrowup · Mar 3, 2026

fast.freddy said:
Must have hit a button accidentally..

V anyway, it sure seems like these little tiny things are just burrowing rt into the medium - and for some reason I thought I would be able to just keep all of this type of stuff outta my grow closet, ughh..
I put up a couple of sticky fly tape's and it got a whole bunch of them, but guess if I'm not killing the larvae then I'll just keep on fighting these little bastards..
I'm sorry for not quite picking up on everything, but
- will these little buggers hurt my seedlings?
- and what will kill them before they hatch or whatever these nasty things do?
It sure would be nice if I didn't have to introduce more bugs into the closet, but whatever it takes I will do!

Thank you so much -

I mean you could start reading all the methods given in this tread.

Then make your own decision on what fits you.

As for if they damage the plant?

There is not one answer to that.

If the plant is healthy and it will tolerate more bugs. It will also be able to produce counter measures that makes the bug like the plant less.

One could argue that some gnats in a healthy grow could be good. Avoiding the plant gets "lazy" .

BeefyBully · Mar 3, 2026

yes, that's why approaches are multi-prong when dealing with infestation. when top dressing the same material is it riddled with larva?
it will have some. More so on the quality and source.

there is no question or argument that we strive for healthy plants. but when something gets out of balance is when things go wrong.
worms: if they get out of control, they will eat plant roots once food source is depleted or leave the area.

yes, plant does develop countermeasures but in time and they need to fully develop.
Bassianna grows with plant at germ.

orggrwr · Mar 3, 2026

fast.freddy said:
Must have hit a button accidentally..

V anyway, it sure seems like these little tiny things are just burrowing rt into the medium - and for some reason I thought I would be able to just keep all of this type of stuff outta my grow closet, ughh..
I put up a couple of sticky fly tape's and it got a whole bunch of them, but guess if I'm not killing the larvae then I'll just keep on fighting these little bastards..
I'm sorry for not quite picking up on everything, but
- will these little buggers hurt my seedlings?
- and what will kill them before they hatch or whatever these nasty things do?
It sure would be nice if I didn't have to introduce more bugs into the closet, but whatever it takes I will do!

Thank you so much -

Yeah this thread seems to have gone off on a tangent, sorry. To answer your question yes the larvae will happily munch on your roots so in large numbers can definitely harm seedlings. In your case a few doses of bti 3 days apart should do it. Keep going till you dont see any new gnats on the sticky traps. In my experience the traps are good for letting you know if there's a problem but won't solve it completely. Good luck

BeefyBully · Mar 4, 2026

Never tried NEM toads, never had to. However, BTI is the way to go for management. Would it still come down to choice?

BeefyBully · Mar 4, 2026

what you take out you put back in...

Week4Bytch · Mar 4, 2026

BeefyBully said:
Never tried NEM toads, never had to. However, BTI is the way to go for management. Would it still come down to choice?
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I'm still on the fence with Nematodes. Lot of growers swear by it. Maybe you have to get it in there early. But, agree the BTI does manage it better. Might try the bottled stuff (liquid form) that I found in Amazon.

orggrwr · Mar 4, 2026

Week4Bytch said:
I'm still on the fence with Nematodes. Lot of growers swear by it. Maybe you have to get it in there early. But, agree the BTI does manage it better. Might try the bottled stuff (liquid form) that I found in Amazon.
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Have never tried the nematodes either but I think i will give them a try in my outdoor grow this year.

Bossman1 · Mar 5, 2026

BeefyBully said:
Never tried NEM toads, never had to. However, BTI is the way to go for management. Would it still come down to choice?
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I will only use build a soil products in my grows !!!!!!!

Week4Bytch · Mar 5, 2026

orggrwr said:
Have never tried the nematodes either but I think i will give them a try in my outdoor grow this year.

Here's an interesting approach to outdoor grows (and it's not tied to just cannabis), planting a variety of herbs and flowers can and will attract beneficial insects. There's a boat load of variety to choose from. You'll want to plant them near and around the grow.

MercDod · Mar 5, 2026

Bossman1 said:
I will only use build a soil products in my grows !!!!!!!

We all have our own preferences.

orggrwr · Mar 5, 2026

Bossman1 said:
I will only use build a soil products in my grows !!!!!!!

Not knocking BAS at all, they have some great products. But a lot of the basic amendments used in building soil can be had much cheaper with equal quality from organic gardening companies that don't specialize in cannabis. Stuff like kelp meal, alfalfa meal, bone , fish ,etc. Again i love BAS but they are expensive for the basics.

Week4Bytch · Mar 5, 2026

orggrwr said:
Not knocking BAS at all, they have some great products. But a lot of the basic amendments used in building soil can be had much cheaper with equal quality from organic gardening companies that don't specialize in cannabis. Stuff like kelp meal, alfalfa meal, bone , fish ,etc. Again i love BAS but they are expensive for the basics.

I believe they source their inputs from select sources near them, your paying a premium because your getting premium. Even their EWC is tops. Your not getting the same by paying less elsewhere. Your getting something but your not getting premium.

BuildASoil tends to use known high-grade sources, for example:
Thorvin kelp meal (cold-water Norwegian kelp, considered one of the best kelp sources)
Crustacean meal from shrimp/crab shells
Camelina meal
Black soldier fly frass
Basalt volcanic rock dust
Oyster shell calcium
Cheap brands often substitute with:
generic kelp meal (unknown harvest quality)
agricultural lime instead of oyster shell
low-grade rock dust or none at all
filler materials
The difference isn’t just nutrients — it’s trace minerals, hormones, and biological food sources.

Putthataway · Mar 6, 2026

Week4Bytch said:
Here's an interesting approach to outdoor grows (and it's not tied to just cannabis), planting a variety of herbs and flowers can and will attract beneficial insects. There's a boat load of variety to choose from. You'll want to plant them near and around the grow.

Marigolds create a toxic response to the bad winged bugs that you don’t want. I spotted this one today that looked like a praying mantis type bug but wasn’t a mantis. Looked like he was going to town on the little bugs that were eating it before winter on my citrus tree.

Gmix · Mar 7, 2026

BeefyBully said:
are you in pots? do you worry about infestation?

No

Why on earth would anyone worry about something that may not happen

Crap if we did that back in the day we’d never grow as every snowflake would worry about being busted

You’ve never tried nematodes yet instinctively know that BTI is better lmfao
What a crock of bs

trygrowup · Mar 7, 2026

I'm gonna wrap it up for my part.
Thank you very much guys.
This has turned out much better than i expected.
I for one have learned some good things here.
Hope others have too.

Personally i'm gonna choose the net method.
I use lids anyway so i'll make some lids of double layer white sheet, but only to cover the top of the pot.
Then if i get runoff i give the bottom tray a few spray of neem oil.
And if it's getting to much i'll take out my vacuum cleaner.
Maybe also the BT thing. First time i hear about that. They don't sell that in grow shops here.

Thanks again for all the input

Pest control concerning gnats in soil

Pest control concerning gnats in soil

fast.freddy

BeefyBully

BeefyBully

BeefyBully

BeefyBully

trygrowup

BeefyBully

orggrwr

BeefyBully

BeefyBully

Week4Bytch

Loyal To The Soil

orggrwr

Bossman1

Week4Bytch

Loyal To The Soil

MercDod

orggrwr

Week4Bytch

Loyal To The Soil

Putthataway

Gmix

trygrowup

Pest control concerning gnats in soil

Pest control concerning gnats in soil

fast.freddy

BeefyBully

BeefyBully

BeefyBully

BeefyBully

trygrowup

BeefyBully

orggrwr

BeefyBully

BeefyBully

Week4Bytch

Loyal To The Soil

orggrwr

Bossman1

Week4Bytch

Loyal To The Soil

MercDod

orggrwr

Week4Bytch

Loyal To The Soil

Putthataway

Gmix

trygrowup

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