HELP! Fungus Gnat Treatment

[duckman]

I'm having an issue with fungus gnats and am planning on going after the larvae with a hydrogen peroxide mix but this is the first time I have tried this as a new grower and my question is: is the intent of the treatment to soak the entire pot or should I just be soaking the top few inches with the mix? any thoughts would be much appreciated!

[Weed Pharma]

I would do two things-
first dry out the grow as much as possible
then use spinosad as a drench.

[duckman]

would like to do as suggested, Weed Pharma, but my understanding is that Spinosad is not legal in Canada. Plus I wouldn't know where to find it! You would not recommend hydrogen peroxide?

[Weed Pharma]

I have not used hydrogen peroxide, as it would kill the good organisms, too- which would hinder a grow.
Fungus gnats are more of an annoyance than a problem, for the most part.
You could do a soil drench with mosquito bits, avaiable in Canada and now labeled for fungus gnat control in the US

[Gingerbeard]

If it's indoor...
Hydrogen peroxide will only kill the fungus the larvae feed on, temporarily. Larvae will die of starvation. Gnats will hook up and lay more larvae once the fungus comes back. And the fungus will come back. In my experience, H2O2 soaking doesn't work. It's cool when your soil boils over, but has never worked for me. I only use it for foliar sprays. Yellow stickes don't get rid of larvae or fungus.
The quickest and easiest thing to do is increase air flow around your soil and pots. Don't give the gnats a chance to land. When the larvae pop, they get blown when they take off. It also helps dry your soil a little faster, reducing moisture.
Again, in my experience, diatomaceous earth will make your soil like moving through glass to bugs and is the best option in the long run. Mix it in with your soil when you (trans)plant and you pretty much eliminate anything that would otherwise mount a ground attack. After the fact is a little tedious as it requires adding treated soil and/or removing the infected.

[Gingerbeard]

Also, fungus grows in soil. Not just the soil at the top of your pot. If you're using basic plastic pots with drain holes at the bottom, those drain holes are always wet enough to support fungus. And larvae. I'm assuming you're already into your grow so adding DE to the top of your pot won't do it. Air is your best bet. Get the pot off the floor a bit. Get fans circulating around your pots as well as over your soil. If fans don't work, I'll lend you a gnat frog.

[duckman]

All in all that's good advice, Gingerbeard, and much appreciated! First thing I did (well, technically the first thing I did was freak) but the second thing was to put a fan right on the soil. I have an elevator I can put her on (she's in a fabric pot) and this should give her more air. BTW what is this Gnat Frog of which you speak?

[Gingerbeard]

Wow! No one ever called me out like that, duckman. No one batted an eye when I said I would shave sharks butt-holes for good nitrogen. I know nothing about how much nitrogen can be shaved from a sharks butt-hole. I don't actually have an actual 'gnat frog.' Nor 'gnat lizard.' Nor a solid google hit on either. How about a gnanteater? They're plausible, yeah? Ever see 'The Island of Dr. Moreau'?
My experience with fungus gnats, however, is golden for regular plastic pots. Have you looked under the pots or drip trays, and such, for fungus? I've had some wind up in my drip tray after spilling a little too much nute water and not cleaning it up, and moving the muffin fan I had on the drip trays. I'm not sure about how long your fans have been circulating. Give it a few days. And vent. Give them a place to go.

[Gingerbeard]

I ran a little experiment for you, duckman.

A small pot filled with soil. A solution of approximately one part 3% hydrogen peroxide and four parts water is poured over the soil. Air bubbles were also being pushed out the drain holes. Bubbling, bubbling, bubbling... a few minutes later... muffin! The soil will not settle back, in my experience, unless external force is applied to push it down. If nothing else, it's a hell of a mess to deal with.

[duckman]

I thank you, Gingerbeard, you have definitely gone above and beyond to assist. many thanks! based on the excellent advice from you and Weed Pharma I'm going to skip the hydrogen peroxide, dry the soil as it has never been dried before and try to get hold of some mosquito bits. perhaps we can avoid the Gnat Frog for now ...

[Gingerbeard]

This frog's for you.

I will always acquiesce to those with more experience. However, I recall several posts about plants being underwatered and the stress it can cause. It just doesn't seem good for the plant. I water/nute as normal and circulate. Adjustments are made as the plants grow. I can't speak to the mosquito dunking but it seems like a good idea. I have a small space with little room to do that sort of thing so would never consider the idea. Drying a plant may kill fungus and mold, but the spores will remain. H2O2 is probably real good for the fabric pots at the end of your grow.

A month or more before your next sowing, buy your soil, open the bag and get as much surface area to the soil to dry it out as much as possible. Toss in the DE and you'll be golden.

[Geofite]

Mosquito dunks or bits is the best and cheapest way to get rid of fungus gnats. I used this for my weed plants and for other house plants that also became infested with the gnats. It works great.

• Mosquito dunks: Mosquito dunks are used to keep mosquito larvae from populating fountains, animal troughs, fish ponds, and other small bodies of water. The product consists of a dry pellet containing a type of bacteria called Bacillus thuringiensis subspecies isrealensis. This beneficial bacteria infects and kills the larvae of flying insects, including mosquitoes, fruit flies, and fungus gnats.
  • To use mosquito dunks: Fill up a gallon jug (or watering can) with clean water and toss in a mosquito dunk. It’s a good idea to break up the dunk a bit before placing it in the water, or you can wait for it to soften before breaking it apart. Let the dunk soak in the water for as long as possible (at least overnight), then remove it from the water (the dunk can be reused) and use this water for fungus gnat–infested plants. The bacteria will have leeched into the water and will now infect and kill any larvae that come into contact with it in the soil. Repeat this process every time you water your plants for at least a few months. https://www.almanac.com/pest/fungus-gnats
• https://www.amazon.com/Mosquito-Dunk...0000AH849?th=1

[quirk]

Orange Oil - 1-2 oz. per gal w/ a few drops of dish soap as a surfactant. Drench and foliar. Completely organic,(limonene) no more gnats. Period.

[Toker1]

Yellow sticky traps for adults and a combination of mosquito dunks in the water and beneficial nematodes ( Steinernema feltiae) in the soil.
https://www.arbico-organics.com/cate...cial-nematodes

[duckman]

I've got the yellow stickies and the mosquito dunks but I gotta say I've been afraid of nematodes ever since that SpongeBob episode...

[Toker1]

Lol. Nice! 😂

[duckman]

thanks to all who replied, the advice is much appreciated...the gnat plant has had a fan blowing on the soil constantly for about 5 days now to dry her out, also put her on a plant elevator to keep her bottom dry. it seems to have had a positive impact as there are no new symptoms showing (random yellow leaves for no apparent reason), I also gave her a good soak with mosquito dunk water...when she dries up a bit I'll get some diatomaceous earth on top as well (can't hurt). with any luck that should keep her safe until harvest in 3-4 weeks.

[Toker1]

Diatomaceous earth washes away too easily. I had better luck with paint strainers covering the soil. Keeps the bugs out and allowed water/nutrients to pass through.

[Gingerbeard]

Applying DE to the surface will work if you apply an inch thick layer and don't water. I'm being facetious. A sprinkling over the top washes away (Toker1) and only covers the tops of surfaces. It doesn't get undersides of soil bits. It's best worked in with the soil before using.

[Toker1]

A few inches of pearlite on top does the same as DE

[duckman]

As my pirate friends would say, Aarrgh!

[Gingerbeard]

Don't sweat, duckman. Fungus gnats're annoying and tickle up the nose. That's about it. They won't hurt anything except a little pride for not growing the perfect crop.

Next time, you have a few heads up. The perlite layer sounds like a great way to treat an in utero infestation.

An ounce of circulation is worth a pound of cure. A pound of cured is priceless.

[HappyDaze]

It can be a bigger problem with hydro setups...I've read that the dirty little phuckers can bring pythium into your rez.

[duckman]

[QUOTE=Gingerbeard;n331969

An ounce of circulation is worth a pound of cure. A pound of cured is priceless.[/QUOTE]...that makes good sense, to me, Gingerbeard. thanks for all the help!

[Toker1]

The larva are quite damaging to roots. Can kill small plants.

[Cali]

Also weakens the plant and then bam pathogens or other pests tag along.