Fungus gnats

[Hunter1]

So I'm having issues with fungus gnats . I know a lot of people say the don't damage the plant bla bla . Well the do . Leafs dying off unhappy looking plants. I can't get shut of them . I've cleaned the room out and waited a few weeks befor restarting but just there always there . I'm using a iws flood and drain system 

When the plants have been fed and water returned the larvey is in the barrel and bottom of the pots shit loads of them .

Local hydro store thought it could be springtails but I've put sticky pads up and I'm catching fly's . I've tried nill gnat or the stuff in the little white bottle that you add drops to your feed and it's just doesn't work . 

So my question is . If I was to put root pouch bags with some pebbles at the bottom to help drainage fill with cocoa then add a layer of Shap sand at the top . Add a dripper system to top feed and just use the flood and drain system to dump the run off . 

Would the barrier of the bag and sand work ? 

Thanks guys any other advice would be great . I've also put a sulpher burner in 4 hours per day 

 

[teehee]

I used Tanlin drops and they seemed to go away. Stop using the stuff and they'll be right back. 

(Don't laugh but...) I also sprayed the outside of my pots and the tent floor with some Mortein, but you don't wanna do that too much, or during flowering if you can help it.

Edited November 29, 2020 by teehee

[Hunter1]

5 minutes ago, teehee said:

I used Tanlin drops and they seemed to go away. Stop using the stuff and they'll be right back. 

(Don't laugh but...) I also sprayed the outside of my pots and the tent floor with some Mortein, but you don't wanna do that too much, or during flowering if you can help it.

I've tried tanlin . Couldn't think of the name in my original post . Didn't seem to affect them even at double dose 

Was just reading a post now where someone has the same issue .

One of the comments were they could Be thrip larvey which maybe would explain the tanlin not working idk

There is hundreds of them in the bottom of each pot and it the Res - brain 

[ratdog]

5 minutes ago, teehee said:

I used Tanlin drops and they seemed to go away. Stop using the stuff and they'll be right back.

 

 

i have some of that kicking around, my gnats are away atm but it's good to know it works, it wasn't cheap!

[ratdog]

2 minutes ago, Hunter1 said:

There is hundreds of them in the bottom of each pot

 

 

springtails? just seen you say it's not them

 

fungus gnats have affected my seedlings before but rarely adult plants, i use sticky traps and hope for the best tbh

Edited November 29, 2020 by ratdog

[chemist]

i use to use layer off sharp sand as a preventative all time ,will help to keep numbers down if there allready. hope u solve the problem or atleast get under control .

 

 

[Hunter1]

After a bit of research i think it's thrips .

I've just never seen the snail trail on the leaves . 

Is there anything to put into the feed to kill the larvey ?

[sonofmum]

If you were in soil, diatomaceous earth would be great not sure how you'd translate that to hydro though (DE are microscopic shards that shred bugs but don't damage roots/plants in small quantities).

[btk1977]

If you've not got any plants on the go yet I'd have another attempt at eradication, I'd run a strong solution of hydrogen peroxide through your system for 48h (its meant to be highly effective at killing the eggs) and have the sulfume hotbox on in there at the same. If you're growing in a tent in a room I would fumigate the room as well as the tent. I'd then drain everything down and let it dry out completely, run the sulfume hotbox while its drying out. I'd then leave it dry for at least 4 weeks (the length of their life cycle) making sure there is no plant matter/anything they could eat in there, ideally keep the space warm as it speeds up their life cycle.

 

The hydrogen peroxide should kill the vast majority if not all of the eggs/larvae and the sulfur should deal with the adults. Then the leaving it for 4 weeks with nothing that they could eat in there would starve to death any particularly resilient ones that managed to survive chemical annihilation.

 

That would be my belt and braces approach. If the 4 week wait wasn't an option I'd be looking at doing a 2nd hydrogen peroxide/sulfume run for 24-48h with cleaning in between the two.

 

 

Your plan with the sharp sand (make sure not to pick up building/play sand as they won't work as well) and the fabric pots should minimise/slow down their impact but think it would just be a matter of time before they managed to get into the coco with such a level of infestation.