How much h202 to kill fungus gnat larvae?

Roger A. Shrubber

Well-Known Member
I have not dealt with fungus gnats since getting Lock Down pads. They're a bit overpriced for what they are, but you could easily DIY some if you're broke. Oh, and they're useless(or a huge pain in the ass) if you have any type of top feed system. I run ebb & flow.
https://www.amazon.com/Lock-Down-Pads-LPD12-1-5/dp/B015IO0SOK
good idea, but is that 10+ bucks a piece?......i'd rather deal with gnats.....(but i'm a cheap bastard....)
and the sizes are confusing me...1.5, 3,6,and 12...? i get the 3, 6, and 12...whats the 1.5? for solo cups? 10 bucks for a 1.5 inch piece of tape?.....
 

Johnny Lawrence

Well-Known Member
https://www.amazon.com/Lock-Down-Pads-LPD12-1-5/dp/B015IO0SOK
good idea, but is that 10+ bucks a piece?......i'd rather deal with gnats.....(but i'm a cheap bastard....)
and the sizes are confusing me...1.5, 3,6,and 12...? i get the 3, 6, and 12...whats the 1.5? for solo cups? 10 bucks for a 1.5 inch piece of tape?.....
Which is why I said you could DIY them. But I'm ocd, so I like everything to look super clean.

As for DIY, there are a couple of companies that make a brush on sticky shit for insects - the only one I can think of is Tangle Trap. And then just yellow construction paper or cardboard and yellow spray paint.

I think the 1.5s are for starter plugs maybe? Not sure, I just run them in my flowering rooms.
 

ltecato

Well-Known Member
How about mosquito dunks containing the Israeli Bt? Will those kill gnat larvae?

Also, I'm amazed that the OP was able to "fry" a Northern Lights plant using the drugstore peroxide watered down 4:1. I can believe that would happen with 30% peroxide but not 3%. Because I semi-routinely use watered-down 3% peroxide as a mouthwash, and have done so ever since my own ma taught me to do it when I was in grade school to treat "mouth ulcers." And believe me, folks, my teeth are NOT whiter than white.

I occasionally add 3% peroxide to liquid fertilizer for sort of voodoo-growing purposes in case the added oxygen helps with nutrient uptake, or if I am worried that I might be overwatering. I've never managed to kill a plant that way.
 

Roger A. Shrubber

Well-Known Member
How about mosquito dunks containing the Israeli Bt? Will those kill gnat larvae?

Also, I'm amazed that the OP was able to "fry" a Northern Lights plant using the drugstore peroxide watered down 4:1. I can believe that would happen with 30% peroxide but not 3%. Because I semi-routinely use watered-down 3% peroxide as a mouthwash, and have done so ever since my own ma taught me to do it when I was in grade school to treat "mouth ulcers." And believe me, folks, my teeth are NOT whiter than white.

I occasionally add 3% peroxide to liquid fertilizer for sort of voodoo-growing purposes in case the added oxygen helps with nutrient uptake, or if I am worried that I might be overwatering. I've never managed to kill a plant that way.

dunks work, but the bits are better, they break down faster into the soil. if you use dunks, crush them up, don't just lay them on top of the pot.
that's a quart of h2o2 to 3 quarts of water....i can believe that would fuck a plant up pretty good, even at 3%. the recommended dosage for 3% is 12-15 ml per gallon for regular use. you can go up to 25 ml per gallon for shock treatment, but you can't use it at that strength for any period of time without taking damage.
there are 946 ml in a quart. that's more than 25...by a bit.....like 38ish times....
 

nicksol86

Well-Known Member
How about mosquito dunks containing the Israeli Bt? Will those kill gnat larvae?

Also, I'm amazed that the OP was able to "fry" a Northern Lights plant using the drugstore peroxide watered down 4:1. I can believe that would happen with 30% peroxide but not 3%. Because I semi-routinely use watered-down 3% peroxide as a mouthwash, and have done so ever since my own ma taught me to do it when I was in grade school to treat "mouth ulcers." And believe me, folks, my teeth are NOT whiter than white.

I occasionally add 3% peroxide to liquid fertilizer for sort of voodoo-growing purposes in case the added oxygen helps with nutrient uptake, or if I am worried that I might be overwatering. I've never managed to kill a plant that way.
I did only use the 3 percent store bought hydrogen peroxide, and It did kill the northern lights. She was young, like only 2 weeks old. Used 1/4 cup 3 percent h202 mixed with 3/4 cups ro water. Fed the cup into the root zone in my hydroton. The plants leaves drooped down the next day and she wouldn't recover no matter what I did to her. I tried saving her like hell by flushing her daily but she wouldn't budge, leaves curled all the way down. I called it a loss after about a week. What does op mean?
 

nicksol86

Well-Known Member
dunks work, but the bits are better, they break down faster into the soil. if you use dunks, crush them up, don't just lay them on top of the pot.
that's a quart of h2o2 to 3 quarts of water....i can believe that would fuck a plant up pretty good, even at 3%. the recommended dosage for 3% is 12-15 ml per gallon for regular use. you can go up to 25 ml per gallon for shock treatment, but you can't use it at that strength for any period of time without taking damage.
there are 946 ml in a quart. that's more than 25...by a bit.....like 38ish times....
I don't use soil. Hydro. So I don't know if the bits would work for me.
 

Failmore

Well-Known Member
i put 150ml of 29% directly into about 15 gallons rez water with the plant in the water. It did not kill the plant. This was 2 weeks after i first started using h202 to treat rot. When i first treated plant with 3% h202 from wallyworld all the leaves drooped down. They stayed drooped for over a week. I assume the plant was in shock, i ended up trimming all roots off and raised the water so i was over the bottom of the net pot. Leaves recovered when i started to see new root growth. Now i treat with 50ml of 29% every 3 days. I put 150ml in by accident and the plant did not die. The only weird thing is my roots are not really growing that much. But the plant is growing about an inch a day at the top.

I'm guessing you messed the roots up and just needed to wait for new ones to grow. Because i had bad drooping after i sprayed the bottom of my net pot with 3% solution straight.
 

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ltecato

Well-Known Member
I've been trying to put in a good word for carnivorous plants such as genus Pinguicula and Drossera. They won't eliminate gnats but they do a great job of trapping and slowly digesting them, providing hours and hours of great entertainment value.

 

5BY5LEC

Well-Known Member
You guys are tripping. Halfway decent covering of sticky traps will eliminate the problem in a couple weeks. No chemicals, no pesticides.

As long as you aren't top watering.
Sticky Traps do great. Get some mosquito dunks for the larvae and problem solved.
Don't use peroxide with BTI or use BTI within 4 days of having peroxide in there.
Sorry BTI = mosquito dunk.
 

5BY5LEC

Well-Known Member
Cut them to strips and put them on top too.
Most of that is dead leaves stuck to the traps BTW. They tend to gather leaf pieces near the end of flower.
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bearded.beaver

Well-Known Member
Any tips on using hydrogen peroxide with a s.i.p.s container(earthbox) I have fungus gnats. I added nematodes 4 days ago. I have sticky traps up.
I was thinking of placing sliced potatoes on the soil surface to draw the larvae to them and then mist them with 1 part 3% peroxide and 4 part r/o water. I don't want to hurt my nematodes or beneficial microbes
 

Roger A. Shrubber

Well-Known Member
Any tips on using hydrogen peroxide with a s.i.p.s container(earthbox) I have fungus gnats. I added nematodes 4 days ago. I have sticky traps up.
I was thinking of placing sliced potatoes on the soil surface to draw the larvae to them and then mist them with 1 part 3% peroxide and 4 part r/o water. I don't want to hurt my nematodes or beneficial microbes
i know what sips are but have never used one. if the soil stays moist all the time, you're NEVER going to get rid of fungus gnats. you can't provide them a nursery and expect them to not use it. i'd think about arranging a fan to blow across the surface of the pots, dry them out a little that way. the potato thing probably won't hurt, just be careful with the h202, use a fine mist and not much of it
 

bearded.beaver

Well-Known Member
I removed the "shower caps" plastic covers that came with them and I have a fan blowing across the soil surface. Hopefully the top will dry a bit. I added some nematodes last friday. but they came in the mail and it was a cold day so I hope they are still alive. I have a bunch of sticky traps. some on the floor under the planters, some laying flat on the surface of the soil and some on little stick things holding them up like a flower.
 

bearded.beaver

Well-Known Member
I'm going to give the potato thing a try I just don't want to hurt mu microbes too much. I will have a earth worm casting tea going on in a few days. I have to pick up more earth worm castings, so that will add some microbes back into the soil. what dilution would you recomend for the spray. I have the 3%. I don't need a gallon. my spray bottle is only 500ml. I was thinking 100ml of peroxide and 400ml of r/o water. thats the ratio I keep seeing
 

Airwalker16

Well-Known Member
I removed the "shower caps" plastic covers that came with them and I have a fan blowing across the soil surface. Hopefully the top will dry a bit. I added some nematodes last friday. but they came in the mail and it was a cold day so I hope they are still alive. I have a bunch of sticky traps. some on the floor under the planters, some laying flat on the surface of the soil and some on little stick things holding them up like a flower.
1/2" of sand on top top of soil
 
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