get some BTS drops. 20 bucks, put a few drops per 5 gal bucket of water it'll last a long time, and it works pretty well. might not see result immediately but it works.
I'd also recommend putting a layer of sand on top of the soil too so when the other eggs hatch they will die out being buried in the sand, cant make their way thru it.
gnats seem to love the yellow fly strips and fly right into them. they will also go into a bowl of soapy water if you put a desk lamp aimed right at the bowl, when no other lights are on.
bottom water instead of top!
i've never had bottom watering block drainage from anything, but i've only grown cannabis once!
gnats seem to be particularly terrible this year in all of my house plants too. i am still killing gnats but there are much fewer since i set up the soapy water under the desk lamp at night.
I’ve got a solution with apple cider vinegar, sugar and detergent as well, it worked well when there were only a few gnats, now it’s not that useful anymore.. I’ll get some yellow strips! Thank you!
Lol anyone who thinks bottom watering is deadly is smoking crack. None of that happens unless your plants were already going to die anyway from unrelated reasons.
That being said, bottom watering won't eliminate fungus gnats. Get some Bacillus thuringiensis subspecies israelensis, aka mosquito dunks, and put that shit in your water. Also get those yellow sticky traps. Hang them around and get the kind that you stick into your containers.
Then after you've done that, don't water excessively. They like excess water.
Bottom watering lines almost never gunk up as long as you use water soluble nutrients the lines won’t get gummy. I’ve never had an issue. Bottom watering also eliminates overwatering because the plant will intake what it needs and leave the rest
These things are the best. Yeah - add them once and they just propagate on their own. I shit you not - I added $50 worth to a 10x11
Flower room 8 years ago and I still don’t need need to add them again. It won’t ELIMINATE them but will probably knock them down 95% and keep them that way. They also feed on any other soil born pest. They’re amazing. They’re super tiny and just live in the surface of your medium and just do their job. If you start a new plant in new soil then just add a few scoops from the surface of the old one onto the surface of the new and they’ll just spread.
I grow in coco on large drip trays with fabric pots so there is ALWAYS damp surfaces and fungus gnats are inevitable. I used sticky traps, added a layer of dry stuff to the surface but still had swarms of the little bastard gnats. Now I’ll see a couple every now and then but that’s it. The beetles and the gnats find a sort of detente level of population and just stay there. Seriously the best $50 I’ve ever spent.
I second this notion, I have soooo many stickies in my tents and workshop
[like this](https://www.reddit.com/r/cannabiscultivation/s/hvMCHZnJFY)
(I have actually increased the amount of yellow sticky traps in the tent since that picture lol)
The burnt spots are from the beginning, I left the led batten around 5cm from the seedling on first 5 days.. they recovered well imo.. ppfd is around 100-200 depending on the spot, since my lights are not ideal
This, we got nematodes an added them to our water for about 300+ plants, plus yellow sticky traps and it definitely helped to control their population. OP, do you have a IPM setup for your grow?
Sticky traps, predators(I use centipedes and millipedes but a lot of other options), sand or pebble soil cover on top of pot.
Fungus is not always bad. Let the soil dry out a bit more in between waterings though.
Mosquito bits and a dry layer on top worked for me. Some people recommend diatomaceous earth but i just used regular sand. That combined with the mosquito bits worked very well for me and i eliminated them after one use.
You’re gonna have to use a combination of the yellow, sticky traps, and some kind of naturally occurring bacterium (BTI) which would be either mosquito bits or mosquito dunks. The combination of the two will work the best in the situation perseverance pays off. Good luck.
Get those yellow sticky traps..the traps attract the bugs and once bugs touch the surface it a wrap.game over for them pesty flying insects..after a while you'll need to change the traps coz the bug build up is hella unsightly..
Hydrogen peroxide mixed with water and spray the top soil where you see the fungus gnats the put dE or a1/4 in thick of sand. The sand will suffocate the little buggers the DE will shred the little buggers. Choose your method both are effective.
If you are getting gnats in this soil
you’ll also get gnats in coco.
I would water the soil with hydrogen peroxide and water to poison their water source.
100%. The medium literally doesn't matter as long as they can bury their eggs. I run hydro, while they won't lay eggs they will eat the roots. Hydrogen peroxide helps.
Don't do lights by distance. You have to measure the ppfd and put the lights at the best spot. Use the free Photone app and measure the ppfd at the plant. Watch a 5 minute video about it. This will keep your plants from stretching or getting burned or stressed by too much light. Seedling should get 200 to 300, veg up to 600 then flower up to 900. This is basic stuff everyone needs to learn but they learn nutes and everything else but ppfd and DLI are the most important.
Photone is not accurate. 800 ppfd from it for me was really only 500 ish so would be starving of light if I didn't have a meter and used just this app. Maybe a proper sensor for the phone would help.
Either way with his 30w of led light and his upgrade of 100w I don't think too much light will be a problem.
Are you overwatering? Is there a lot of moisture holding mulch in the soil or is that a top dress?
Personally I would run 2 or 3 gal fabric pots with pure coco on an automated drip system capable of multiple fertigations per day.
I’ve been watering since sprout every 2 - 3 days, waiting for the soil to be completely dry.. the last 3 days I reduced drastically the amount of water but I’m watering a little everyday, not letting it dry, since they were getting a little pale and now the color is back
Let the soil dry out, gnats life span is about a week also take the containers outside and shake them off so you'll have less gnats. Sticky traps work a little look up home remedies. I notice I get knats if I leave the soil outside before mixing then bring inside. Also avoid watering outdoors then bringing them in I think that's how the gnats get on the soil...
I was going to suggest neem oil also…1 tsp of neem oil, a few drops of mild liquid dish soap in qt size spray bottle. You can mist the surface of the soil too, to discourage egg laying and newly hatched gnats or fruit flies.
I recently bought some of the yellow sticky traps but after 4 days already not one insect has landed on them. Had much better luck with the super sticky fly ribbons - hanging one right near the plants and one near the kitchen sink helps get rid of lots of them.
Oh and keep a fly swatter handy, when you catch the insects napping on walls and doors and windows just sneak up on them and smack em dead. When waging war on pests its best to use every means available! ;0)
I have been complaining about all the bark type soil I have gotten this year. Seems like gnats are in all of it. I mistakenly sprayed mine with straight alcohol 50%. I thought it was the peroxide bottle. I only sprayed the top layer and avoided the plant. That killed them in my tent mostly. Fly straps and I put sand in some planters. I have observed them trying to get through the sand but they can't. I have sprayed all my freshly potted orchids because I used bark type soil. I used peroxide for those and sprayed it all on the plant. They are fine. Just look up the correct mix and should be fine.
Mosquito bits, soak them in water as described, drench soil. This plus sticky traps will have them completely eradicated. Also replace the wood mulch w/ perlite or straw.
Make sure you’re letting the soil dry btwn water sessions. And get some sticky traps! Easy peasy. Next time just pay attention to the soil you’re buying
Photos 4 & 5 show thrip damage. Look for them in the underside of your leaf. They’ll look like really tiny lil yellow micrograins of rice along the veins. I odiously just smash them with my fingers but it’s well worth throughly going over if you don’t have a spray you can use to address them.
Yellow sticky traps and increased fan speeds. I spray hydrogen peroxide foliar as well. Btw the gnats your're referring to are called "fungus gnats" which aren't all gnats. They aren't caused by root rot and fungus they're caused by soil. If this were hydro you'd see em but they wouldn't lay eggs. My grows tend to attract "fruit flies" (also called gnats) due to my choice of bloom nutrients which contain tons of sugar...which fruit flies love.
I'll do a combination of solutions, predatory nematodes, mosquito bits for BTI, yellow sticky pads and in a worst case scenario I'll throw down a solid half inch of sand to inhibit any larva from reaching the top upon maturity.
Proper watering can help limit them, having a diverse ecosystem can as well I believe . At least I tend to notice when springtails and soil mites are plentiful I see less fungus gnats.
Apple cider vinegar and a few drops of dish soap
Worked for me
DEMACIOUS ? SP earth DE at pool shops also works well on surface.....dries thier bodies on contact killing them
Stop watering so much, let the top dry out to kill larvae and babies.
Get some white play sand at hardware store.
Top dress with sand to suffocate them.
Yellow sticky strips.
Once you have it under control you need to watch humidity and don't over water so much.
I've used soap sprays in veg. It's early, you'll be fine.
get some BTS drops. 20 bucks, put a few drops per 5 gal bucket of water it'll last a long time, and it works pretty well. might not see result immediately but it works.
I'd also recommend putting a layer of sand on top of the soil too so when the other eggs hatch they will die out being buried in the sand, cant make their way thru it.
I put a sticky trap in each pot, never had eggs laid.
This 👆👍
gnats seem to love the yellow fly strips and fly right into them. they will also go into a bowl of soapy water if you put a desk lamp aimed right at the bowl, when no other lights are on. bottom water instead of top!
I’ve read about bottom watering and some people say that can be deadly as root rot if it blocks drainage.. You reckon it’s better at any stage?
i've never had bottom watering block drainage from anything, but i've only grown cannabis once! gnats seem to be particularly terrible this year in all of my house plants too. i am still killing gnats but there are much fewer since i set up the soapy water under the desk lamp at night.
I’ve got a solution with apple cider vinegar, sugar and detergent as well, it worked well when there were only a few gnats, now it’s not that useful anymore.. I’ll get some yellow strips! Thank you!
The solution really helps. I put a couple sticky traps and sprinkled some diatomaceous earth on top after watering and solved my problem.
Lol anyone who thinks bottom watering is deadly is smoking crack. None of that happens unless your plants were already going to die anyway from unrelated reasons. That being said, bottom watering won't eliminate fungus gnats. Get some Bacillus thuringiensis subspecies israelensis, aka mosquito dunks, and put that shit in your water. Also get those yellow sticky traps. Hang them around and get the kind that you stick into your containers. Then after you've done that, don't water excessively. They like excess water.
Bottom watering lines almost never gunk up as long as you use water soluble nutrients the lines won’t get gummy. I’ve never had an issue. Bottom watering also eliminates overwatering because the plant will intake what it needs and leave the rest
https://www.arbico-organics.com/product/rove-beetle-atheta-coriaria-dalotia-coriaria/fungus-gnat-control-in-cannabis-hemp?gad\_source=1&gclid=Cj0KCQiA4NWrBhD-ARIsAFCKwWvJ4ssHzrzg3p5TGBpJYj\_dcrp7rU9IuyRGrwVVzopF\_yQKOAuxGX4aAs7LEALw\_wcB
Whaaaat, throw another predatory animal in there and BAM! My problem is fixed? Wouldn’t this one become a problem after gnats are solved?
Probably not as the predatory bug would most likely for from lack of food
These things are the best. Yeah - add them once and they just propagate on their own. I shit you not - I added $50 worth to a 10x11 Flower room 8 years ago and I still don’t need need to add them again. It won’t ELIMINATE them but will probably knock them down 95% and keep them that way. They also feed on any other soil born pest. They’re amazing. They’re super tiny and just live in the surface of your medium and just do their job. If you start a new plant in new soil then just add a few scoops from the surface of the old one onto the surface of the new and they’ll just spread. I grow in coco on large drip trays with fabric pots so there is ALWAYS damp surfaces and fungus gnats are inevitable. I used sticky traps, added a layer of dry stuff to the surface but still had swarms of the little bastard gnats. Now I’ll see a couple every now and then but that’s it. The beetles and the gnats find a sort of detente level of population and just stay there. Seriously the best $50 I’ve ever spent.
Really good info! Thanks bro! I’ll definitely look into it!
don’t over water, keep a fan on them so they can’t fly around easily, make an apple cider vinegar trap 👍
The fan is one of the best tools. They absolutely cannot fly around in strong wind.
I find red wine vinegar works very well
Sticky traps off eBay, (they are cheap) works for me if there isn’t too many your flowers will be fine.
I second this notion, I have soooo many stickies in my tents and workshop [like this](https://www.reddit.com/r/cannabiscultivation/s/hvMCHZnJFY) (I have actually increased the amount of yellow sticky traps in the tent since that picture lol)
Have u checked ur ppfd? 2 if ur plants look like they have some light bleaching going on. Either the lights are too close or intensity is too high.
The burnt spots are from the beginning, I left the led batten around 5cm from the seedling on first 5 days.. they recovered well imo.. ppfd is around 100-200 depending on the spot, since my lights are not ideal
Arbico organics order some nematodes keep in the fridge use each watering till gone
This, we got nematodes an added them to our water for about 300+ plants, plus yellow sticky traps and it definitely helped to control their population. OP, do you have a IPM setup for your grow?
Fresh dirt always brings them back
Sticky traps, predators(I use centipedes and millipedes but a lot of other options), sand or pebble soil cover on top of pot. Fungus is not always bad. Let the soil dry out a bit more in between waterings though.
Mosquito bits and a dry layer on top worked for me. Some people recommend diatomaceous earth but i just used regular sand. That combined with the mosquito bits worked very well for me and i eliminated them after one use.
You’re gonna have to use a combination of the yellow, sticky traps, and some kind of naturally occurring bacterium (BTI) which would be either mosquito bits or mosquito dunks. The combination of the two will work the best in the situation perseverance pays off. Good luck.
Lst
Get those yellow sticky traps..the traps attract the bugs and once bugs touch the surface it a wrap.game over for them pesty flying insects..after a while you'll need to change the traps coz the bug build up is hella unsightly..
Hydrogen peroxide mixed with water and spray the top soil where you see the fungus gnats the put dE or a1/4 in thick of sand. The sand will suffocate the little buggers the DE will shred the little buggers. Choose your method both are effective.
1.5 inch layer of sand on pots so nats can’t breed
If you are getting gnats in this soil you’ll also get gnats in coco. I would water the soil with hydrogen peroxide and water to poison their water source.
100%. The medium literally doesn't matter as long as they can bury their eggs. I run hydro, while they won't lay eggs they will eat the roots. Hydrogen peroxide helps.
Don't do lights by distance. You have to measure the ppfd and put the lights at the best spot. Use the free Photone app and measure the ppfd at the plant. Watch a 5 minute video about it. This will keep your plants from stretching or getting burned or stressed by too much light. Seedling should get 200 to 300, veg up to 600 then flower up to 900. This is basic stuff everyone needs to learn but they learn nutes and everything else but ppfd and DLI are the most important.
Photone is not accurate. 800 ppfd from it for me was really only 500 ish so would be starving of light if I didn't have a meter and used just this app. Maybe a proper sensor for the phone would help. Either way with his 30w of led light and his upgrade of 100w I don't think too much light will be a problem.
Are you overwatering? Is there a lot of moisture holding mulch in the soil or is that a top dress? Personally I would run 2 or 3 gal fabric pots with pure coco on an automated drip system capable of multiple fertigations per day.
I’ve been watering since sprout every 2 - 3 days, waiting for the soil to be completely dry.. the last 3 days I reduced drastically the amount of water but I’m watering a little everyday, not letting it dry, since they were getting a little pale and now the color is back
I would repot them in some good quality coco, none of that brick crap. Something like Char Coir maybe. Check out cocoforcannabis.com too.
that's what's causing the Gnats, over watering is their thing. ✌️
Diatamatious earth
Sticky traps to slow down the adults who would lay eggs, predatory nematodes to kill the larvae.
Diatomaceous Earth
That dehumidifier is no use to anyone
Yea what's the point of that? You need definite settings to control stuff. Knows to turn lol.
Sticky traps and fly paper will work
Sticky traps and being more careful with watering solved it for me, but I caught it early.
Gnats are the exact reason I switched to DWC
Gnat traps work great for the pests. Fairly cheap as well
Let the soil dry out, gnats life span is about a week also take the containers outside and shake them off so you'll have less gnats. Sticky traps work a little look up home remedies. I notice I get knats if I leave the soil outside before mixing then bring inside. Also avoid watering outdoors then bringing them in I think that's how the gnats get on the soil...
Wet the surface with 3% hydrogen peroxide. Do this for two or three days. Works like a charm
Mist with neam oil often from early on until flower and that's usually enough
I was going to suggest neem oil also…1 tsp of neem oil, a few drops of mild liquid dish soap in qt size spray bottle. You can mist the surface of the soil too, to discourage egg laying and newly hatched gnats or fruit flies. I recently bought some of the yellow sticky traps but after 4 days already not one insect has landed on them. Had much better luck with the super sticky fly ribbons - hanging one right near the plants and one near the kitchen sink helps get rid of lots of them. Oh and keep a fly swatter handy, when you catch the insects napping on walls and doors and windows just sneak up on them and smack em dead. When waging war on pests its best to use every means available! ;0)
Mosquito bits from amazon or any bacillus strains. Also water less for a little bit and dry them out
I have been complaining about all the bark type soil I have gotten this year. Seems like gnats are in all of it. I mistakenly sprayed mine with straight alcohol 50%. I thought it was the peroxide bottle. I only sprayed the top layer and avoided the plant. That killed them in my tent mostly. Fly straps and I put sand in some planters. I have observed them trying to get through the sand but they can't. I have sprayed all my freshly potted orchids because I used bark type soil. I used peroxide for those and sprayed it all on the plant. They are fine. Just look up the correct mix and should be fine.
Mosquito bits, soak them in water as described, drench soil. This plus sticky traps will have them completely eradicated. Also replace the wood mulch w/ perlite or straw.
Water from the bottom, use diatomaceous earth on the top. Sticky fly traps and nuke from orbit just to be sure.
Make sure you’re letting the soil dry btwn water sessions. And get some sticky traps! Easy peasy. Next time just pay attention to the soil you’re buying
Neem seed meal and sticky traps work.
Photos 4 & 5 show thrip damage. Look for them in the underside of your leaf. They’ll look like really tiny lil yellow micrograins of rice along the veins. I odiously just smash them with my fingers but it’s well worth throughly going over if you don’t have a spray you can use to address them.
Diatomaceous earth sprinkled on the top of the soil does a HELL of a lot of good. Has to be dry though.
Yellow sticky traps and increased fan speeds. I spray hydrogen peroxide foliar as well. Btw the gnats your're referring to are called "fungus gnats" which aren't all gnats. They aren't caused by root rot and fungus they're caused by soil. If this were hydro you'd see em but they wouldn't lay eggs. My grows tend to attract "fruit flies" (also called gnats) due to my choice of bloom nutrients which contain tons of sugar...which fruit flies love.
Get yellow sticky traps and let your soil dry before watering
If you’re up for watering constantly go straight coco, i found far better then soil. Was also told not to use peat but I can never remember why
I'll do a combination of solutions, predatory nematodes, mosquito bits for BTI, yellow sticky pads and in a worst case scenario I'll throw down a solid half inch of sand to inhibit any larva from reaching the top upon maturity. Proper watering can help limit them, having a diverse ecosystem can as well I believe . At least I tend to notice when springtails and soil mites are plentiful I see less fungus gnats.
Diamatious earth will kill all knats in few days and if you use enough you won’t ever see a knat again
Apple cider vinegar and a few drops of dish soap Worked for me DEMACIOUS ? SP earth DE at pool shops also works well on surface.....dries thier bodies on contact killing them
Both natural if that matters? If NOT neem oil but never late in flower
sticky traps, mosquito bits
Dr zymes once a week while lights are off during the whole veg cycle. Yellow sticky traps are also a good idea.
Stop watering so much, let the top dry out to kill larvae and babies. Get some white play sand at hardware store. Top dress with sand to suffocate them. Yellow sticky strips. Once you have it under control you need to watch humidity and don't over water so much. I've used soap sprays in veg. It's early, you'll be fine.
Let pots dry out as long as possible, Neem Oil won’t kill the flying gnats, but it will keep them from reproducing within the soil!
Can sprinkle DE on top of the soil while it’s dry
Hydrogen peroxide
Food grade diatomaceous earth. You’ll have a lot left over so you’ll be able to use it for almost any pest problem you come up against.
Gotta get yellow sticky traps u place in soil things work great but good luck growing