Fungus Gnats.. HELP!

I've been growing for a few years in my current location with out a single pest problem. All of a sudden I start seeing fungus gnats flying around.
I've been using "Gnatrol" as a means of control by pouring it into my 8" pots.
I have my plants in small rockwool cubes that sit in lava rock.
I also have sticky traps for the adults. I've treated once a week at 8 tsp per gallon .I've done the treatment 4 times already, but with no luck on reducing the population. What the hell do I have to do to get rid of these little pricks?
Please help!

Try hanging no pest strips and spraying with garden safe 3 in 1. You can pick it up a the home depot. It is $4.99 a bottle.

Also, be sure that your RockWool is completly covered by the LavaRocks. The fungus gnats lay thier eggs in the algae on top of the RockWool. When the eggs hatch into larve, the larve feeds on the root system of your plants. You have to kill the algae. Like all plants, algae needs air, water and light to survive. By cutting off the light to the algae, you will kill the algae.

Vi

THanks guys, I've been reading about pyrthrin bombs and sprays, has anyone used these to any success?

Also, my plants look green and healthy. Monday starts my fifth week of flowering and the plants seem to be OK. but I'm growing 2 new strains and I'm not sure if their progress is normal or being effected by these bugs.

I've got them too...didn't know they were fungus gnats! oh no! i didn't have them until one of my ladies got into full bloom...I do wonder if they're attracted to the smell?

OCgirl said:

i didn't have them until one of my ladies got into full bloom...I do wonder if they're attracted to the smell?

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yea they are little stoners. and if you water the plants with molasses in the water that attracts them too

I read that if you cover your soil/soilless medium with potato slices the gnats will lay eggs on the potato slices. Throw them away after three days and repeat till gnats go byebye. Not sure if this works, just figured id pass along.

GL dude

goto a Home improvement Store and buy some diatomaceous Earth topdress your pots with a light layer of that .. no more pests

No pest strips and store bought sand for top dress works for me. I have also "bombed" the area, but you'll have to do it a few times about a week apart, but I wouldnt do it too close to harvest.

Fallen Buckshot said:

goto a Home improvement Store and buy some diatomaceous Earth topdress your pots with a light layer of that .. no more pests

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That sounds good to me.

When I had a problem with them I added a top dressing layer of 2" of clay pebbles and hung an insect strip...... they were very soon gone. Top dressing stops them laying eggs in your soil, thats the key to breaking the cycle

ATTENTION PEOPLE!!!!!! LURE THE GNATS TO THEIR DEATHS, buy somw apple cider vinigar, pour some in a couple of bowls an disstibute aroung the problem areas in two days it will have then completly gone

neem oil neem oil neem oil

i had a lot of them till about a week before harvest
then they all disappeared
wtf?

on my first gen, flowering ladies, i used the sticky yellow fly traps and let the soil dry completely between waterings
on my second gen clones, i added 1 inch of sand over the soil, used the yellow fly traps, etc.

those little assholes seemed to survive all those counter-insurgency measures for a month and then suddenly, gone

weather related ? not sure. (upper midwest - we went form avg 85 deg to avg 65 in a couple weeks

i tried neem oil for about two weeks resistant little fuckers, even if organic i dnt like using pesticides if i can refrain from doing so
the apple cyder vinegar really works trust me and do make sure u let the soil dry out between waterings the dry soil creates to dry
of a climate to lay eggs in, in which case their even more intrested in the moist bowl

would just apple cider work? I don't have the cider vinegar, but do have apple cider. Little bastards. I have every other type. I'm going to run a little test.

I had luck with this product called goGnats.

It is based on cedar oil. It killed the larvae and killed or drove off the adults..

cerebralvibrator said:

That sounds good to me.

When I had a problem with them I added a top dressing layer of 2" of clay pebbles and hung an insect strip..

Click to expand...

P
okay guys. This guy is Right! I have the same problem. All of us that are using organic soil purchaced this problem. They were already in the soil when you bought it. As eggs then you add plants for them to feed on and mature that's when they become adults. They are attracted to you're soil beause it's organic. The diatemaceous earth is not a toxic chemical and only kills the adults when the walk onto it. It dries them up like poring salt on a slug. Do this and in 48 hours you will no longer have adult gnats. Re apply it (if needed) every 10-15days to get all of them and keep them out!!!!

This thread has some ideas you can try.
https://www.rollitup.org/marijuana-plant-problems/216537-self-diagnose-your-plants.html
I'm very interested in seeing if the Tobacco Juice works, if you're willing to try it.
Take 3 strong ciggeretes soak them over night in water
Boil it for 2 to 3 miniutes, let it cool off and spray the plants 3 to 4 times a week. You can add safer soap if you like to the mixture.
(make absolutly sure you use gloves/face protection while handling and spraying)
For spider mites it says to add chili pepper powder. I imagine you can try it for gnats too.

Personally I've only used Mite X and it got rid of Thrips in one application, didn't kill the eggs though, I had to do that myself. In your case sand should kill the eggs by suffocation.

And I have Lady Bugs on the way now to use as a prevention measure, I'm sure they'd be ideal on the gnats if you don't want to use sprays. You can get them at nurseries or if they don't have them this time of year you can order them through Home Depot's web site.

That thread I posted doesn't list lady bugs for mites though it does llist them for other pests. In Wikipeidas explanation of lady bugs it says they eat just about any soft bodied bug their size or smaller, so I don't really know till I've tried them myself. But I don't think I'll ever have gnats since the humidity is usually 20% here.

Hope some of this helps. Good luck.

P.S. That thread is paperclipped, so I assume the info is dependable.