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Tired of having to fight gnats every time you get a brick of coco?

Drop That Sound

Well-known member
I swear now most grow shops and the trucks that ship in pallets is infested with em, they probably fly out of the organic soil bags nearby and crawl into the little holes in the packaging of every other medium around including bricks. but then again who knows maybe the main suppliers of soil\coco let the gnats swarm and have a contract with the pesticide manufacturers so they all stay in business!

It all usually ends up stored in the same dirty warehouses/hydro shops, sometimes more than a year after delivery until someone buys it too, and could have been exposed anytime since it was made...

They need to vacuum seal coco bricks if they are gonna be shipped to a warehouse or store.. If they really do have eggs in it when it gets compressed that's crazy.

I just today finally seen flyers crawling/jumping out of my coco pots, I knew better than to bring that shit into my nothin' but 3.75 net pots with a handful of hydroton per plant (even huge plants) bare root R/DWC only garden that hasn't had any gnats ever until I expanded that brick just over a month ago.

Maybe just a coincidence but I didn't even see them though until I added floralicious+ so can't blame really botanicare, .. Either way they seem to be loving it all the sudden. I just sprayed green cleaner on all the plants and didn't see a single one not even 2 days ago, even misted the top of the pots as I rotated it and banged it around.. didn't see a single one..crazy!
 

Drop That Sound

Well-known member
Anyways I wonder.. how would breaking up a dry compressed block first and throwing it in a large vacuum chamber overnight would work, instead of baking or boiling.

Basically would be like sending your bricks up into space, and only fictional aliens can survive that am I right? implode the eggs and turn em inside out even in the middle of the brick..

About to go Ripley style, wrap tin foil around the stocks and top rims on the plastic pots, prod around and cook the mf'ers with a mini torch right in the coco. Then maybe try to electrocute the larva right out of the pot with a stun gun and 2 probes with wires. If that doesn't work I'll be back to try the conventional methods.

Rather be hand watering extra dwc buckets now than offering a nesting home and then having to evict fly's. Thought I would make it easy and pickup a cheap brick, shoulda known better, ah well lol at least i'll learn how to rid them for good this time and if there is a next time right when I expand a block.

Coco has always a pain in the ass more than half the time for me, always something... one of the main reasons I quit using it. might even just shake it all off and transplant them into bigger net pots that probably don't even cost as much as a worthwhile product, and toss them into some buckets like I should have in the first place....
 
You're too funny Drop That Sound...

I think heat is the only way I heard.

Don't think vacuum would kill the eggs. The eggs may not have enough surface area for a vacuum to explode them.

A big microwave would probably work great. Microwave only acts on things with water content. Those little eggs are probably mostly water.
 

Loc Dog

Hobbies include "drinkin', smokin' weed, and all k
Veteran

Drop That Sound

Well-known member
Holy crap Loc what if a queen tardigrade mated with a spider mite and made babies! We'd all be screwed haha! Nasty looking little suckers..
 

Drop That Sound

Well-known member
A little more off topic but I don't believe in space anyway, NASA's bogus pictures, faked moon landing, heliocentric "theory", operation fish bowl to the van allen belt, etc...

Back on the topic of gnat's though, i'm on my way out to the garden to test my new "weapon x gnat piss'er off'er" out. Something that probably hasn't been done before.

Been letting the coco dry out to test it full force, honestly haven't seen any since I tried something the other night, lets see how it works in a direct attack :)

Even if it doesn't rid them permanently I will be back shortly to entertain my IC folk with some pics of gnats being F'ed with and pissed off tonight, which I am sure you will all enjoy. Hahahaha!
 

onavelzy

Active member
Veteran
Personal update on what has/hasn't worked for me so far. I started my first grow ever in the 2nd week of February. It's a clone grow in bagged coco in a tent, quarantined for first two weeks in a nearby closet under LED's then moved to the tent.

I used boiling water for the initial batch of coco when I put the clone starters into solo cups and then boiled some more when I up potted to my final 2 gallon containers about 4 days ago. I also hung yellow sticky traps day 1, in the closet and also in the tent. I sprayed with Spinosad twice while I had them quarantined in solo cups.

Haven't seen a fungus gnat yet. The only thing the sticky traps have caught so far is my hair when I bumped into them trying to lower my light.

I remain vigilant but so far, soaking the coco with boiling hot water seems pretty effective, simple, cheap and environmentally safe. I can see where it would be a hassle if you're doing large volumes of Coco though. I'm just running 7 plants, so it hasn't been that big of a deal.

Hope that helps.

Take care,

Ona
 
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Drop That Sound

Well-known member
Oops, almost forgot to post what I tried. It really did piss of the flyers, but I didn't want to wait around and experiment on a whole crop to see if it actually eradicated the gnats. That and I don't like letting the coco dry out to be able to do it as it seems to affect the plants worse than the pest problem.

So I ended up hitting the plants with hydrogen peroxide 3%, at a 1 to 4, HP to water ratio first. Then went to the store and bought a jug of mosquito bits, some sticky traps, and an 8 pair pack of panty hose to wrap around the pots.

It took me like 30 minutes in the "hosiery" section to figure out that size Q is the biggest. Learned quite bit about panty hose browsing the net on my phone while in the isle. Got a lot of dirty looks though and was uncomfortable as hell LOL.

Anyways they ended up not fitting over the pots anyway so had to cut em and use tape but there is no way they can fly through it now haha.

My other option was gonna be a layer of play sand on top, and was gonna insert irrigation line down through the sand when I hookup a pump and timer soon. Right now I just been hand watering.

I honestly don't even think ill need the mosquito bits, just hit them with the HP one more time to make sure I got all the larvas. I will remove the panties to see if the flyers are still able to live underneath it where I can't see soon, if they are then maybe i'll use the bits too.

As promised here is some pictures of weapon X. It is a very high percentage pepper mint flavored E-juice concoction I made that one sniff will burn your nose and make you cry, I blew it in through the bottom of the pots until it came up through the coco and watched every single flyer scramble to gtf outta there. They flew of all disoriented and pretty sure they died from nicotine overdose coating them. It was a great site to see, and honestly I had only seen a few since, but figured I better be safe then sorry.

-Drop
 

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Whenever I have to use a store-bought bag of medium I place it into an old pillowcase cut the top of the bag of meduim open put it inside of a cooler and pour 3 or 4 gallons of boiling water into it. This has eliminated fungus gnats and thrips very effectively. Great thread.
Peace
 

RB56

Active member
Veteran
So I've done some testing. Fungus gnats are absolutely being transported in bricks of coir. I reconstituted a handful of my usual Amazon cheapo Kempf brick inside a closed one gallon pail with a yellow sticky trap stuck to the interior side of the lid. Checked it every couple of days. After about 12 days, there were two fliers stuck to the trap. Not likely to have been contamination. Weirdly, time to fliers suggest they are traveling as pupae?

In any case, I repeated the test with Kempf coir I reconstituted with enough water that you can pretty easily stir it - 7-8 gallons added to the brick? I added two quarts of 3% HO, stirred it up and let it sit for 48 hours. Rinsed and charged as usual. Repeated the 1 gallon bucket test and found no fliers. Obviously need to repeat both sides of the test if you really wanted to be sure.

For me it doesn't matter. I started using the technique
in this thread. in soil but carried it over to coir. I have not had a fungus gnat problem since. I did not know that fungus gnats came in bricks of coir because the technique above seals them into the medium. Fliers can never emerge. Maximum one generation of gnats. No infestations.
 

Drop That Sound

Well-known member
Once in awhile I think SM eggs get slipped into the batch too, more likely the outside of the bag though, but I have wondered... I spray the wrappers off as soon as I get home from the shop.

Crazy to know there are little alien eggs waiting to hatch, dormant for possibly years!

Any coco used indoors I for sure boil, then add Mosquito Bits.

Outdoors now I just expanding it, toss in some MB's and mix it up, then lay my old used hot shot NPSs in the same tote and letting it sit for a week or 2 with the lid on.. Heck with boiling that much coco.

Pest free is the way to be ;)
 

beta

Active member
Veteran
I've tried virtually everything there is to permanently eradicate fungus gnats in a perpetual garden, and here's what consistently works:

1) Boil all coco bricks to hydrate

2) Top dress every pot with crushed up mosquito dunks

MosquitoDunks.jpg


I'm not sure why the crushed mosquito dunks work better than Gnatrol and all of the ag specific products, but they definitely do.
 
X

xavier7995

It is kind of slow but i get my coco good and wet and then stick it in the oven for an hour or two at 400, then turn off oven and leave it overnight. I use big stock pots to do it, i do that with both new coco and if reusing to kill anything i can.
 
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