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How To Kill Fungus Gnats With Hydrogen Peroxide

Discussion in 'Sick Plants and Problems' started by Reverend Bud, Feb 5, 2010.

  1. I love this trick of using H2O2 to kill fungus gnats, as I've been using it to sterilize everything in the grow room.

    Perlite was a less dusty substitution I tried for the sand.

    Lawn fabric was a substitute for women's hosiery.

    What really worked for me was Bti or mosquito dunks in my watering container. This version of Bt is on the organic approved list, but I was still nervous about the random, unlisted ingredients used to hold the little cakes together. I'm hoping the hydrogen peroxide will be a safer, much cheaper solution for treating the soil.

    Thanks again (to the original poster) for sharing the great info.
  2. #23 Herb Connoissuer, May 23, 2013
    Last edited by a moderator: May 25, 2013
    i had the same issue and planted some clones into a potting soil, which i visualy inspected and seemed fine. i had used the same soil for my mothers, no bugs in that bag so i figured i was good, and realized one bag had an aphid infestation i was trying to figure out prior(tossed that bag). and the others had fungus gnats, including the bag i used for my clones :( I removed about an inch of the top soil and ceased watering for about a week now.
    any ways, dont know how much of this soil your planning on using but you can certainly bake it in the oven. get a baking tray or caserole dish or something and fill it with soil. mix in some water enough so you can make a ball with your fist but it still breaks apart easy. hopefuly the infestation isnt too bad or you might be mixing bug stu :D
    cover that sht with tin foil, get a meat thermometer, get the temp up to atleast 180 degrees and keep it there for 30 min. dont let it go over 200 degrees or ur hooped. i filled two massive pots full of cooked dirt...probably took me about 10 hours :S pressure cooker would be prime, you can use a microwave but sounds a bit harder to make sure you have the right temps
    btw wicked post about the peroxide thanks. im gonna try that
  3. Fantastic idea i must say! i used a 29% peroxide and diluted it about 24:1, bout a cup a pot, just enough to cover the top. still saw them for the next couple days but it seems to have helped a ton. between removing as much top soil as possible, drying that soil right the F out, and then a dose of that juicy stuff. My problem might even resolve its self come time for flower.
    Thanks a lot!
  4. My only worry about trying this is I was under the impression that healthy potting soil is alive with beneficial microorganisms and the H202 would wipe them out too. How important are they in a healthy system? I only see a handful of the gnats so far so I'm not too worried but preparing for the worst.
  5. im not sure how important they are. i can say ive been watering like this for a couple weeks now. the plants look very healthy, filled out nice, maybe a little slow but they look great.
    However...i still apear to have bugs. starting to think maybe it could be root aphids... sticky traps are gettings filled up nicely, and after another hydrogen peroxide water...which is all ive been giving them... they are still quite noticeable in a few pots. i think it hasnt helped as much as i hoped
  6. Hm I did water last time at a 50% recommended concentration but i bought molasses to regenerate my bennies after the gnats have gone adios.  But on another forum I did see it stated several times that it would kill the good bacteria, however if you are not doing organic I dont think it will impact you much.  I am not full organic but I am close so it is a bit important to me that the good guys live and continue breaking up that organic matter for more nice natural nutrients :]
  7. Hello! Oh how happy I am that I found this thread! I hope someone can help me!!! I actually have NO houseplants of any kind inside my home (because it's like a darn cave in this apartment), but now that it's warm again we are plagued with these horrible fungus gnats!!! Ugh!!! We moved in to this place last September, and they existed until it got cold, and now here they are again. (Yes, they were here the first week we moved in, but the management had no freaking idea what I was trying to describe and acted like I was nuts!) I guess we must have 'fungus' if they are here, but it's beyond me where because we are clean people and nothing has changed in our habits! Anyway...has anyone had this problem, and HOW do I GET RID of them??? They are attracted to apple cider vinegar, just like fruit flies, ad I have some in a cup in which they go and drown in (YESSSS), but if it's like last year, they will simply BE here ALLLLL SUMMER until it gets cold again!!! (We're in TN.) SO the cycle will be to dump the vinegar when about 25 of em are floating around dead, then put a new batch out. UGH!!! Please advise!!!! :hello:
  8. can you find where they are mainly situated? I know there is ways of... maybe not eliminating them but controlling them if you can find where they are nesting.
  9. I soooooo wish I could find where they are situated!!! They just seem to appear!!!! But they like the kitchen and two bathrooms the most. Last year when we moved here I thought they were fruit flies, but I knew that there was NO rotting fruit or veggies because we JUST moved in!!! (I'm a total health nut, and I never EVER allow any food to get to that point anyway--I'm pretty anal that way! Lol!) The biggest factor is that all winter we had NONE, but as soon as the temps started staying in the 70's, 80's, and 90's they showed up again. I never leave any windows or doors open, especially now that the A/C has to stay on....but I always kept a screen closed when the sliding door was able to be left open. I've set out a fruit fly trap of apple cider vinegar in a cup, and they are extremely attracted to that and go in there and die. (There are 6 of them in there since yesterday.) But I know they are fungus gnats after endless research, because last year I just couldn't figure out WHY we had fruit flies when there was no rotten ANYTHING laying around! These little suckers, though, DO like to land on the occaional banana...even though it's not rotten. Ugh. And I'll find them laying in my dog's water, and any water I have sitting out (like when I'm soaking grains or beans for sprouting). Thanks so much for your inquiry!
  10. hmm. i know my buddy had some in his house and cant seem to get rid of them. I know they like moisture. i have them in some pots, and i wouldnt notice them untill i watered. i would have to assume that they would be living outside..and finding a crack or something to enter the house. Kind of like ants, but their entrances are usualy a little easier to spot. tricksy little bastard i must say.
    I use DE, diotomaceous earth, basically a fine silicone like razor blades for bugs :), but like i said i know where they are living...only thing i could think to try and tame them would be some carniverous plants, get a butterwort or some of the easier ones to care for
  11. Hmmm, carnivorous plant?? I hadn't heard of this! But you can bet I'll be getting one or two to try!!! Thank you!! :metal:
  12. http://en.wikipedia.org/wiki/Pinguicula
    np, theres a bunch of different types, pitcher plant, venus fly trap, etc...some eat different insects than others
    I know butters are gr8 for aphids and fruit flys n shiet, but they certainly wont eliminate your problem :D
  13. Thank you! I will certainly be getting some! It's SOOO worth a try!! :D
  14. do you have an old tiled shower by chance, i used to get ants who would burrow through the grout n sht between the tiles, had to redoo the bath room :(
  15. It is tiled. But this is an apartment, they already think I'm nuts when I tell them about these flies. I think it stems from some kind of deeper sewage issue actually, because I've never had this happen in my life and I live the same way I always have! :) They are only in the bathroom in very small numbers though...they like to be out in the kitchen area moreso.
  16. Ick!! good luck sir!
  17. Hey only did two treatments with the hydrogen peroxide water solution but didnt notice any change, in fact after the last watering i saw hundreds of little white 2-3mm long larva things hopping around everywhere which is far more than i saw ever before so just going to say fuck it at this point, house plants show no signs of damage to the roots so i just got pyrethrum spray for the foliage and yellow sticky traps.  The traps are amazing! within 2 days 4 of them have caught near 100, i didnt even see that many around.  I would definitely not bother with the H202 unless there is serious damage visible.  
    As for the infestation, very strange, cant say ive heard of anything quite like that.  As far as I know the adults are very short lived, so if I was you I would go all commando and seek and destroy those little bastards because theyve got to be coming from a concentrated source and it sounds like that source is in your apartment.  Try the sticky traps, alot cheaper than vinegar if your going to look at a more long term method of handling them.  Ive noticed when i spray a perimeter of raid around gaps in doors and around windows ants will not tread near the sprayed area for weeks.  If there are small holes you suspect they could be coming through this could help.  Good luck!
  18. Lol Rusty! That's EXACTLY how I feel with them....I go all COMMANDO for sure!! Haha!! I just realized something as well...I think my sewer theory is correct because I always see 1 or 2 in the spare bathroom, and we don't even use that tub. Ever. There is no moisture in that bathroom, or fungus for that matter. So it's simply got to be the sewage system. Although it's not like there are swarms anywhere, it's just that they exist...always. :p
  19. yea get some raid draino haha if there is such a thing. plumbing is a shitty place tohave them id have to assume
    And i feel ya rusty. i did the h202 treatment for like 2 weeks with 29% and still saw the lil buggers, they almost got worst after a while. So i would have to agree with the h202 not being as good as expected. and about going commando.... so i transplanted them into a slightly larger pot. itook the plants out used my spray setting on my sink foccet to get most of the infested dirt off. heres one of my favorite parts, after i got alot of the dirt off, i used a pre mixed solution of h202 and water and dumped a couple cups of that onto the remaining soil and root ball...it made a gr8 sizzle :D
    then with the new pots, used a layer of perlite on bottom, layer of DE, then added new soil and put the plant into the new pot. layered the top of that with perlite then another layer of DE
    of course iv been using a billion sticky traps the whole time, and it just gets the fliers, from the hanging strips to the ones that stick right into pot. iv noticed about 10on the sticky traps since i went commando compared to about a 100 before, not to mention you just had to shake the pots and out they fkn come...not no more!!!! this has so far been the only thing thats worked fo me, oh and i did this outside of my tent, and washed the tent extra good before putting the plants back in

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