Help!!! fungus gnats

Paul bones

Active Member
So I open my Grow Tent today and found about a dozen fungus gnats flying around and moving slowly I just ordered yellow sticky traps off of Amazon they will be delivered tomorrow and I was also looking up some videos on YouTube that said using 3% hydrogen peroxide will kill the larvae? is this true? I'm planning on using one part hydrogen peroxide and 4 Parts water somebody please let me know if I should or should not do this
 

spliffendz

Well-Known Member
Okay spliff I'm going to do it tomorrow is the ratio that I'm going to attempt the correct ratio? One part hydrogen peroxide and 4 Parts water? Or should I try something different
i was advised to use it like that by a chemist but never got round to it, so wait for second/third opinions, there are many many posts on gnats btw ;)
 

DCcan

Well-Known Member
3rd on the Gnatrol/Mosquito bits. Anything with Bti
It's a natural bacteria, no issues.
Make sure you get Bti , not Btk...thats a related organism for caterpillars
 

OldMedUser

Well-Known Member
if you're near any toilets/sinks/drains, throw some bleach down there too
Toilets and sinks that get regular use aren't a problem but a sump like mine was. The previous owner had left some malathion so I put a bit of that in there and sealed off the access. Bags of soil often come pre-charged with gnats that the adults got to while they were sitting around waiting to be sold. Most bags have little air holes in them and that's all they need or a tear in an otherwise sealed bag. Keep all dirt bags far away from the grow room. That means the kind dirt comes in too and not just your shady friends. ;)

i was advised to use it like that by a chemist but never got round to it, so wait for second/third opinions, there are many many posts on gnats btw ;)
I happen to be a retired chemist but it's my many years of growing pot that have taught me all sorts of things like peroxide won't get rid of them. The peroxide will oxidize anything organic so when it's less than 1% it's already pretty weak. Might slow them down a bit but if used often it will also slow down your plants by oxidizing feeder roots too.

The best remedy is to get some Gnatrol or those mosquito dunks that have an effective bacteria in them targeted toward larva like gnats and mosquitoes. That stuff really works but if there is a source of new adults then it's an ongoing battle.

:peace:
 

OldMedUser

Well-Known Member
Can that product be used during flowering I'm 3 weeks into flower and I don't want to cause any harm
No problem. It goes in the soil so doesn't do anything to the buds. The adults don't harm the plants. They just mate and the female lays her eggs back in the soil and the male dies. Yellow sticky traps right in the pots can help get rid of the adults which eventually gets rid of the larva.

:peace:
 

spliffendz

Well-Known Member
Toilets and sinks that get regular use aren't a problem but a sump like mine was. The previous owner had left some malathion so I put a bit of that in there and sealed off the access. Bags of soil often come pre-charged with gnats that the adults got to while they were sitting around waiting to be sold. Most bags have little air holes in them and that's all they need or a tear in an otherwise sealed bag. Keep all dirt bags far away from the grow room. That means the kind dirt comes in too and not just your shady friends. ;)



I happen to be a retired chemist but it's my many years of growing pot that have taught me all sorts of things like peroxide won't get rid of them. The peroxide will oxidize anything organic so when it's less than 1% it's already pretty weak. Might slow them down a bit but if used often it will also slow down your plants by oxidizing feeder roots too.

The best remedy is to get some Gnatrol or those mosquito dunks that have an effective bacteria in them targeted toward larva like gnats and mosquitoes. That stuff really works but if there is a source of new adults then it's an ongoing battle.

:peace:
yeh sorrry this is the problem with the internet, too much misinformation and contradictions, was just reading an article on it last night :)
 
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