Question about pesky fungus gnats

[Hashdriveway]

So I'm about to restart my grow cycle. Last cycle we had a fungus gnat problem, hoping to avoid that this time around. Local grow store suggested the following tip for dealing with larvae in mature plants. He said this:

"Increase o2 levels from 1.5mL per 4litres to 5mL per 1 litre."

I'm just wondering if this is safe? My o2 is 29%. He said my plants would be totally fine, but using over 13x the recommended o2 levels seems scary to me.Any input would be greatly appreciated.

So my real problem comes with trying to keep the fungus gnats away from my seedlings. I cannot hit the young guys with o2 because they are way too young. Grow store told me to make sure I don't over water and it should keep the gnats away from seedlings. Apparently neem oil isn't sold in Canada. But he promised me o2 would work just as well.

I've read that putting a layer of perlite at the top of the soil slows them down. I'm also gonna pick up some yellow sticky traps, and probably set some apple cider vinegar traps to catch the adults. Any information at all on controlling these gnats would be greatly appreciated. Cheers and happy growing!

 

[Scientific]

O2? I'm assuming you mean hydrogen peroxide, H2O2? There seems to be a mania for unnecessary flushing and for dousing everything with H2O2 in cannabis culture lately.

Traps, yes. High quality, steam sterilized soil, yes. Perlite at the top and bottom of the pot, yes. Keeping the soil surface dry with good air circulation, yes. Maybe others will have more suggestions.

You can buy neem oil at Canadian Amazon.

Good luck and have fun.

 

[Hashdriveway]

Thanks for the quick reply,

Yes, I meant h202. I'm guessing my local grow store wants me to use it because it's probably their highest profit margin for fungus gnat control. Either way I don't mind, I have quite a bit of h202 at the moment. So do you think 5mL per 1L is too much considering the hydrogen peroxide is 29%? And also considering the reccomended dose on the bottle says 1.5 mL per 4L. This new dosing would effectively put it at 20mL per 4L which kinda scares me. I'm just really afraid of frying them with too much hydrogen peroxide.

 

[Canuckbuds]

Thanks for the quick reply,

Yes, I meant h202. I'm guessing my local grow store wants me to use it because it's probably their highest profit margin for fungus gnat control. Either way I don't mind, I have quite a bit of h202 at the moment. So do you think 5mL per 1L is too much considering the hydrogen peroxide is 29%? And also considering the reccomended dose on the bottle says 1.5 mL per 4L. This new dosing would effectively put it at 20mL per 4L which kinda scares me. I'm just really afraid of frying them with too much hydrogen peroxide.

I made a thread the other day about this same thing. One guy said 2-3 inches of perlite in top of your medium keeps them away.

 

[Hashdriveway]

Thanks man just read it now. But that also doesn't answer my original question. Btw Do you know if it's safe to keep the top layer of perlite from veg all the way up to harvest?

 

[Canuckbuds]

I'm a rookie myself but can't see why not. I'd rinse the perlite first though if it was me.

 

[Canuckbuds]

I'm a rookie myself but can't see why not. I'd rinse the perlite first though if it was me.

Also, too much h2o2 may kill any beneficial bacteria of fungi in your growing medium, as Scientific explained to me the other day.

 

[Scientific]

Do you know if it's safe to keep the top layer of perlite from veg all the way up to harvest?

Perlite is inert. It's just a mechanical barrier to flies. You can leave it on all the time.

 

[Autoflower420]

Thanks for the quick reply,

Yes, I meant h202. I'm guessing my local grow store wants me to use it because it's probably their highest profit margin for fungus gnat control. Either way I don't mind, I have quite a bit of h202 at the moment. So do you think 5mL per 1L is too much considering the hydrogen peroxide is 29%? And also considering the reccomended dose on the bottle says 1.5 mL per 4L. This new dosing would effectively put it at 20mL per 4L which kinda scares me. I'm just really afraid of frying them with too much hydrogen peroxide.

H2o2 is more for bud rot get some mossy dunks and break them up and water with them it will wipe every one out and eggs and young

 

[TheDuderoni]

Recently dealt with these bastards after they nested in the soil. This is a small indoor grow in a dry climate. Removed as much of the top soil as possible without exposing the roots and then layered vermiculite on top, roughly 2". Equip a handheld vacuum to kill as many as possible before they mate or nest. Left as is until she needed water again 3 days later at which point removed all the old stuff, watered, then replaced with new dry vermiculite, about 1/2".

 

[little kitten]

O2? I'm assuming you mean hydrogen peroxide, H2O2? There seems to be a mania for unnecessary flushing and for dousing everything with H2O2 in cannabis culture lately.

Traps, yes. High quality, steam sterilized soil, yes. Perlite at the top and bottom of the pot, yes. Keeping the soil surface dry with good air circulation, yes. Maybe others will have more suggestions.

You can buy neem oil at Canadian Amazon.

Good luck and have fun.

That's what I just ordered, some sticky pads and some Mosquito Bits. They both help til there's an infestation. Then mix the peroxide/water...and sprayer,,,,,IF you treat your babies like I do.LOL