Here We Go -- Gnats in the house before my grow! Oh No!


My grow should begin next week just waiting on more gear. So in the meantime… I purchased some flowers from wally world a few days ago and lo & behold the gnats are starting to get busy in here ughhh :roll_eyes: Please someone tell me how to be rid of them before my girls go into buckets and what’s the best thing to use if they should attack my babies. I’m growing auto’s in DWC/Bubbler buckets. Thanks Bunches.


I will tag some friends here for you, I guess they know something about this little :smiling_imp:. Just give them some time to respond :+1:
@MattyBear @Onlythebest79


I’m not running DWC and I’m only having issues in my medium. Are they in your tent? Food grade Diatomaceous Earth (DE) is safe to use all over the plant.


I’ll tag @seeddog he helped me but I ordered gnat-nix to try and solve my issue tried DE food grade. It worked on gnats but the larvae was a different story.


If your plants are not in that soil yet then microwave the soil then run 1 part h202 / 4 part water solution through there. THEY WILL ALL BE DEAD!! You will kill any beneficial organisms in there also if there are any so you will need to take that into consideration when adding future amendments


Oh wait, your in dwc? I’ve never had a gnat problem one in Hydro. They live in the soil medium. They can’t live in hydroponic mediums, at least I’ve never had them in any hydroponic medium


That would kill them but it would also sanitize the soil and the soil would be devoid of nutrient value… heard people baking soil but it will make the house smell. @TDubWilly … I guess you could try that and then re introduce nutrients to the soil, like you mentioned


@Key2THC , @Onlythebest79, @MattyBear I transplanted all our house plants in fox farm soil and then covered all plants with a half inch layer of Gnat Nix that I got through Amazon . I also got those yellow sticky fly paper sheets and hung them right on the outside of the buckets and containers .I think useing both will work the best . I’m not sure about when growing DWC . I guess lots of sticky tape . I hope this helps you .


Potato traps place sliced potato halves on soil the knats will favor them to lay their eggs after several days change them this disrupts the life cycle let soil dry out at same time. In hydro use sticky traps cut a donut to surround base of plant and top of netpot rinse medium with peroxide solution 10ml/L


Thanks everyone for all the great suggestions. I’m definitely getting some sticky paper and I have food grade DE… from lots of reading on this they say you can apply DE or Gnatnix on top of your grow medium even in Hydroponics, but, for the most part those disgusting creatures don’t affect hydro systems. I say; Better safe than sorry!!


This company makes a gnat spray, i had them really bad after getting clones infested as a gift. They were BAD! This stuff sprayed daily for like 3 days, misting top of soil good and sides of containers. Then i used some natural stuff with waterings as mantanice like a week later.
Also the stick pads for windows work great on the sides on containers, and i had good luck with fly strips laying on floor between the containers.
Potatoes work good on soil pushed in a little but be sure to remove them every few days or the larva go into them and just turn to flys in the potatoes instead of soil.
Also if not too bad tobacco, garlic, cayenne pepper and neem oil boil then simmer for a bit take off heat strain while still hot add the neem oil (i used a shot glass in about 3/4 gal water) let cool and ph, it will be high. And use as soil spray,or soil drench. This kills and repels alot of pest including aphids and spider mites, catapillars and most bettles. I use this mix in my veg/fruit gardens, and cannabis.Hope this helps good luck.


If all else fails,big home improvement stores carry spinosad (EG. Monterry Insect Garden Spray). It’s so safe you can use it on organic veggies and tobacco right up to a week before harvest. Deadly to insects. You may need to spray once a week for a few weeks to kill the next generation.


Thanks for the info BigFella… It may come to that cuz I’m seeing more gnats in the house…even tho I took all my flowers outside. I’m glad to be here in good hands cuz I have enough challenges ahead of me growing ‘auto’s’ in DWC for the 1st time…am trying to correct anything that would invite any complications!!


I had a few in my tent at the beginning of my current grow. Lost a couple leaves to them. I relocated a wolf spider from my garage to my tent. Never saw a gnat again.


Unfortunately, those gnats are probably flying aphids. When aphids have overrun their plant they hatch a generation with wings. Those guys fly off and find new plants. Their children don’t have wings. So aphids can get into your house, greenhouse, anywhere. They are so small they can come into your carefully isolated “clean room” with you as you enter and you never see them.

I got some inside during my last grow. I used spinosad inside my house and it was fine. Totally non-toxic and no smell. I love the stuff.


I have a spider, too. When I bang on the wall a couple times he springs into action and patrols every single plant. Its a hoot to watch! Also have a mini bug zapper that rides on my light mover. Its on a timer to run for 30 minutes after lights out…anything winged flys right to it. The spider is much more entertaining, though.


I had this issue and found that covering the soil top with a layer of DME prevents the gnats laying and the larvae cannot tunnel through and die in the soil. Been Gnat free for three weeks now. I am still top-feeding (first grow - in a gro-tent). I just put in some cheap funnels for feeding and watering and don’t disturb the DME. Last week we had an ant problem in the house and a few found their way into the tent - but walking on the DME does them no good either.


Putting a layer of diatomacious earth on top of the soil makes a concrete-like layer when you water. Then the water soaks in very slowly. It does kill insects that need dirt, but you should know how it affects your watering.


That’s why I have funnels down about 2 -3 inches, unless I mess up watering it does not affect the DME cover. If I do spill then I let it dry and remove and replace.
I got 50KG for A$45 so have plenty for my 6 pots - I have used about 20% - mostly for the initial coverage.
I cover the funnels with the yellow sticky papers so nothing goes in or gets out :slight_smile: