Fungus Gnats

My girls are just 2 weeks old (OG God Kush cuttings) hydro drip fed system in hydro corn, 1st week they were thriving.
Then the bottom leaves started going yellow with what look like small patches of some kind of mould.
I had been having problems with my emitters plugging up and at first thought it was a result of that, ie not enough feeding as it appeared as though the plant was pulling food out of the leaves instead of storing it in them.
2 days ago I found a little fly laying beside one of my buckets, identified it as a fungus gnat and things started clicking.
The larvae eating the roots (as they are known to do).
Applied 30 ml VectoBac to my (20 liter/5 gal res) yesterday, and today I added another 30 ml.
The stuff claims to work quickly, starting to kill larvae within 24 hr.
I can't say if it's working yet, but today I found another dead adult.
Since this started, I would notice things getting slightly worse daily, but today there seemed to be no further damage.
Shifted the top of the medium so I could see the rockwool they came in, saw no movement anywhere.
Also checked the bottom of my buckets and saw no signs of bugs.
Obviously hoping this gets them.

bt should take a few days to kill them, but afaik they stop feeding pretty quick. mosquito dunks are bt as well btw.

My Home Depot didn;t have those dunks, they were my 1st option and I ordered some online for future.
My local grow shop had the Vectobac, grabbed a bottle for $15.

Seeing new growth all around, roots and shoots!

I'll give it another blast after 6 days to wack any that were still eggs.
I haven't seen any more adults yet, but some dreck in the runoff when I flushed everything today.
Fresh nutes usually gives things a nice jump.

in the future you can just add dunk to res and leave it there or crush and add a little powder to soil mix. ewc or ewc tea does same thing. btw most hardware/garden stores have mosquito dunks, have seen in grocery stores a few times as well. glad thats working for you, the bt should stay alive in the medium for a while but more wont hurt. tc

Got my dunks, I'll try a piece in some stockings in the res in future. Crazy new growth, the girls are happy, I'm happy. Even some of the bottom leaf I thought was gone is greening up again.

sand trick for soil medium helped me pretty well, and neem oil. but u doin hydroponics ) gl stayin fungonat free

Seeing some more bottom leaves yellowing again, also saw another dead gnat and a couple fliers. Sprayed plants with Schulz's, added another dose of Vectobac to the res. Root eating little bastards.

Stinky Buds said:

Seeing some more bottom leaves yellowing again, also saw another dead gnat and a couple fliers. Sprayed plants with Schulz's, added another dose of Vectobac to the res. Root eating little bastards.

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I started a thread today about the use of Hydrogen Peroxide for these little bastards. I will keep everyone posted as to my results.

Last week I saw some more yellowing and found I had root rot, I sospect due in part to me turning down the aeration in my res because the Vectobac I was treating the fungus gnat larva with was foaming a lot. I went and got some 29% H2O2 (hydrogen peroxide) and added 8ml to my 5 gal res 2 days ago after flushing everything. The smell (Pythium) was much reduced yesterday, no further yellowing. Changed the res again yesterday and it was still clear when I got home today. Added another 8 ml today. Still seeing white healthy roots, removed 1 piece of rotted root that was till white on top. I just cut the rotten piece away.

good luck man, hope.all turns out well

sorry to hear that rr sucks. two methods for dealing with it that i have had success with are chlorine https://www.rollitup.org/hydroponics-aeroponics/655319-using-bleach.html and the hiesenburg tea https://www.rollitup.org/dwc-bubbleponics/361430-dwc-root-slime-cure-aka.html. hth & gl

Stinky Buds said:

Last week I saw some more yellowing and found I had root rot, I sospect due in part to me turning down the aeration in my res because the Vectobac I was treating the fungus gnat larva with was foaming a lot. I went and got some 29% H2O2 (hydrogen peroxide) and added 8ml to my 5 gal res 2 days ago after flushing everything. The smell (Pythium) was much reduced yesterday, no further yellowing. Changed the res again yesterday and it was still clear when I got home today. Added another 8 ml today. Still seeing white healthy roots, removed 1 piece of rotted root that was till white on top. I just cut the rotten piece away.

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God Damn man! Way to go. I am still reading and reconsidering and working up the nerve to do it. I noticed a dramatic imrovement with the mosquito dunks. However the mosquito dunks only kill the larvae and the eggs hatch a week or so later and you start all over again. If this H2O2 works, I gotta try it and NUKE them!

Thanks! The smell is getting less and less, more root popping out the sides of my mesh pots. Some leaf damage, but new growth is looking ok.

I haven't seen any signs of fungus gnats since I started fighting the rr. I suspect the BTi got the larva and just before the rr started, I sprayed with Shulz's Fungus Gnat spray to wipe out any adults, I hardly saw any adults, but did see a few. I also stopped the feeding during dark hours and cranked up the air movement. Feeding is 15 minutes of drip time (using 2 gph emitters) every 4 hours, skipping 2 while the lights are off. I switched to 12/12 last week just before the shit hit the fan (rr set in).

Fungus gnats are history.
Pythium is on the run and the plants are recovering.
The last step I took was the final kick to the Pythium.
I changed the res every second day while dealing with this, dosing the 5 gal res with 8 ml of 29% H202 to clean up the roots.
The smell just kept hanging in until I took several small fans clipped to the edge of the effected pails with the airflow directed straight down into the medium (hydro corn).
I've rotated the 4 fans between the 6 girls and have driven the stink out.
New growth is looking great.
This has been a bitch, but was inevitable when switching to a new system.
Now I know...

You need an ovicide, a repellant, and a contact killer. I use Gnatrol to kill the larvae and eggs. I make a solution of cinnamon, neem, cayenne, garlic and dr. bronners peppermint soap and after a watering spray the surface of my coco and the bottom 1/3 of my plant. This combination Gnats DO NOT like at all. 5 days with a pest strip and another application of the spray and Gnatrol and no more gnats. If you decide to make this spray, just be careful. Wearing a mask and eye protection is a good move. Also it has a strong smell so dont apply it too late or hit any flowers. Best of luck.

I used Vectobac (another form of BTi, an ovicide - same stuff as Gnatrol and mosquito dunks) and switched between Schultz's House Plant and Indoor Garden Insect Spray (Pyrethin) and then Shultz's Fungus Gnat Spray (resmethrin 0.25% and tetramethrin 0.25% ). Haven't seen and gnat on the stickies since, but then the Pythium/root rot kicked in.
That was dealt with by increased res changes, increased aeration in the res, adding H2O2 and drying out the media a lot more, all during week 1 of flowering.
Plants took a hit, but lots of new growth now.