So, the consensus on fungus gnats is....?

[chrill]

I have a major gnat infestation..I was wondering if there is any consensus here on what works best? Half of you say mosquito dunks rock, half say they suck. 3 people say sand, 6 people say sand doesn't do anything. Azamax? Azatrol? DE? Give up? I just want to get rid of the bastards without affecting my plants. I have 6 plants in 3 gallon hempys, 28 days into flower under 1200 watts. I haven't used any chemicals on them this grow. has anyone dealt with gnats in perlite/vermiculite before? What do you recommend? The leaves are starting to discolor like they have a deficiency, but I am most irritated with them getting stuck in the resin.

 

[OsWiZzLe]

I take mosquito dunks and use half of the pack in 20 gallon of water...works awsome....azatrol/azamax follow up would be ideal....

 

[chrill]

I take mosquito dunks and use half of the pack in 20 gallon of water...works awsome....azatrol/azamax follow up would be ideal....

Ok, 1 for the dunks. the thing is, I'm working with 3 gallons of water every feeding. How does this break down from 20 gallons? Do I want to include them with every feeding?

 

[OsWiZzLe]

break up 2 of them in the 3 gallons of water....use them twice a week maybe 2 total times


get some yellow sticky traps if you can to catch the adults...even better if you can use a small can of doctor doom or something similar ... the dunks are going to kill the babies beneath the surface your medium ...

 

[Claude Hopper]

get some yellow sticky traps if you can to catch the adults.....

Make your own sticky traps with a recycled Pennsoil container. Just cut out a square piece from the front and back and coat with a bit of oil. Every few days just wipe on a bit of fresh oil. I used tons of these in my old market garden. Outside I always used STP engine treatment because it is exceptionally sticky.

 

[chrill]

Thanks for the words Wizzle and Claude. I will stop at the hardware store tonight and get some dunks and sticky paper. I'll let you know how it works out!

 

[puff adder]

I would REALLY look closely, and make sure you don't also have root aphids. I am a proffessional fungus gnat farmer, and both times I had a big explosion of fungus gnats, I also found I had root aphids.
The RA flyers look very much like fungus gnats, and I never found fungus gnats on my plants, only RA flyers.
Fungus gnats are a nuisance, but I've never had them really affect my plants, RA on the other hand are totally evil.

I read up here, and found out about Bayer Tree and Shrub (Imidicloprid) and it took care of the RA and also the fungus gnats as well. The mosquito dunks have a permanent residence in my resevoirs, but they never were totally effective, not like the Bayer Tree and Shrub. It is systemic though, and only should be used in veg, up to week 1 of flowering. Also, get LOTS of the yellow and blue sticky traps, hang the yellow ones high near the ceiling, and at the base of the pots. Put the blue ones at the bases as well, they help.
IMO the key is prevention. In veg, I hit my girls with Bayer Tree and Shrub, Floromite, and Eagle-20 for powdery mildew, and once again when I flip, growing has been trouble-free since I started doing that.

Read up here about the RA, in my experience they often are found together. The RA kill the roots, and the opportunistic fungus gnats set in. Good luck.

I just checked your pic again, and I'd say those bugs in your pic are definitely root aphids. The long wings are a giveaway. Bayer Tree and Shrub!!
It may be too late for these plants to use any systemics, read up in the RA thread, there's other things you can use to hopefully get through this run, but you're in for a fight.

 

[crunchy]

Hello,

I had fungus gnats too on my grow, so i used sticky paper traps, wich i disposed in between the plant's containers, with fungus gnat off
http://www.hg-hydroponics.co.uk/fungus-gnat-off---250ml-407-p.asp
And neem oil wich i sprayed on top of the soil and on the sides of the plant's containers in the container's openings.

They're practically eradicated and my plants are doing a lot better.

 

[mugenbao]

Obviously there is no consensus

And just to add my $0.02, I tried mosquito dunks and a whole litany of other things to no avail, then tried some predatory nematodes. Damn those things work well. Works for root aphids and a whole host of other pests, too.

 

[igrowone]

no useful suggestion for your current troubles, other than i have had the little pests myself
but for prevention, pasteurization of the soil is a very definitive preventative
heat soil to 180 degrees F for a hour or so, no nasty pests survive, beneficials are preserved
a routine process in commercial greenhouses, i swear by it

 

[JWP]

The people who say the sand does not work just arent doing it right. You need to use the sand as a preventative measure.

When i repot before flower i use rockwool in the bottom inch or two of the pot to plug the drain holes and sand on the top.

The gnats have a hard time with the rockwool in the drainage holes and cant get past the sand either.

If you dont plug the drainage holes with rockwool theres no point using sand because the gnats will just come and go from the bottom of the pots.

 

[bongbong]

Bro those look way too large for gnats. They may be adult thrips its hard to tell from the pic. Spinosad is the cure for thrips. I hate those gnat bastards too. My hydro shop guy says he's got a barrel of gnatrol in the back I may try using that again. The dunks aren't totally effective and they clog my spaghetti drip lines over time. Good luck

 

[livingluminarie]

Fungus Gnats does affect the plants health. I've had them bad last year until I used sm-90. Sm-90 2 or 3 times and never had them again. Tried aztrol/azmax, neem, mosquito dunks, and yellow cards with very little success. Still use the yellow cards just to let me know if I have any problems earlier than finding out later.

Another product that has worked wonders for me is Mite-Rid which is very effective for Fungus Gnats too.

The Gnats were a result of some bad clones that I received, but usually it's from over watering or poor drainage containers.

 

[puff adder]

Those are root aphid flyers, I'd bet money on it. Can you take a close-up pic? The RA and fungus gnats often go together. Look closely, are the wings shimmery and iridescent, and do the wings go past the bugs butt? Fungus gnats have roundish wings, that don't protrude past their butts. Plus, I've never found a fungus gnat actually on my plants, whereas I Have found RA flyers on the plants, exactly like you have.

The fact that you have RA flyers means that they've gotten to a big enough population level somewhere that they morph into the flyers to find new places to infest. This means you need to act quickly. I'd bet you have both RA and fungus gnats.

RA flyers look very much like fungus gnats to the untrained eye, there are many stages to this bug, even a couple different flyer versions, probably just different life stages/ages, but they are evil. Start researching now, some people have been successful fighting these as late as you, because you can't use Imid at this point. Remember this in the future.

 

[Smoke Buddy]

SAND...

I'll say it again. SAND...
I have no idea why people keep using toxic poisons for this when the information has been out here for a while.
Its easy, nontoxic and works pretty much instantly. All the fliers will be landing on the sand and they cannot get thru. They will be flying all over in a panic.. In the next few days you will notice piles of dead gnats on the floor. Meanwhile the larva in the soil are not able to get out and so they DIE... It works great.

As JWP said, if you didnt get success with sand you didnt do it right which I cant even imagine how one would do it wrong.

Remove the sand after a couple weeks and enjoy your lack of gnats...

or you could try poison.

peace

 

[puff adder]

Sand will do nothing for the root aphids. At least for me, responsible use of some nasties has made growing fun and issue free.

RA are nothing to take lightly, if it were just fungus gnats, then IMO other methods might work fine. RA are a "deal with it or start over" kind of issue that requires the heavy artillery.

 

[chrill]

Well guys, you have given a lot of great advice and insight, and I don't really know what happened, but I don't see any flyers or crawlers around. I didn't do anything to the girls, the bugs seem to have just went away for now. The temperature has been around 60 with the lights off, and 75 on, which I don't think is cold enough to put them in hibernation...so whatever happened, I hope it stays this way. I'll keep you guys updated. Happy Tokage, and have a great weekend fellas.

 

[livingluminarie]

SM90 eliminates all fugus gnats after 1 week of use. I've had over hundred plants and have used the sand, plastic, bombs, azatrol, etc...nothing compares to the effectiveness of SM90.

I used sm90 as a drenching method 2 or 3 times, Done. Yellow stick cards are good to have as a sign of fugus gnats.

 

[maggot420]

I live in the middle of fruit orchards so it's pretty much impossible to get rid of gnats but one thing that works good to catch the adults is apple juice or wine poured in a bowl or cup with a couple drops of dish soap.

It's best to cover it with saran wrap with some holes poked through then tighten it with a rubber band.

 

[neon3kgt]

iv been useing gonats for about a month now and it helps but doesnt seem to eleminate all of them. i also use sticky traps and that seems to help with enough of them above the soil line.