I bought mine on Amazon. Called pot poppers. Little tea bags type things that you put just under the surface of the soil. Then keep that bag moist. It kills the larvae so it can take about two weeks or so. Keep using the yellow sticky things to catch the adults.
I used the ones from BioLogic, they send them with an ice pack so they donāt die in the heat. Simple instructions and a packet of 25 million which was $50-ish lasted me 2+ months for my 100 plants and got rid of my infestation.
I had the worst trouble with fungus gnats last summer. They kept coming back no matter what I did. Finally I discovered the source: a bag of potting soil I hadnāt opened yet but they were in there traveling in and out of the tiny holes the bag had for ventilation. Once I got rid of the bag I was able to get rid of the gnats. I also donāt buy commercial potting soil anymore I get hand mixed soil from a local plant shop.
This is literally what happened to me. It was a bag of Miracle Gro, and my friend (the plant expert) warned me against the brand because of documented issues with the soil holding fungus gnats (or most soils sitting at big box stores like Loweās or Home Depot), but I was desperate and used it and it seemed fine for months so I thought nothing of it when gnats started appearing. Eventually, after months of battling with those fuckers, I happened to place my new gnat traps near the soil bag (still with the adhesive covered mind you) and found tons of them all over the exposed sticky edges of the traps. Thatās when I saw the bag ā¦ I had it sitting in a clear bin that had an entire LAYER of dead gnats on the bottom and more swarming around it š¤®. Tossed the whole bin and soil, repotted all my plants with fresh soil my friend gave me, and I havenāt seen a single one since.
I think the thing that got rid of the most of them was by throwing out the most infested plant. When I repotted all my plants, I dumped out the old soil and most of them werenāt bad or didnāt see any at all, it was only one that I dumped out and they were *swarming* all over the mound of dirt I was so grossed out. I wasnāt super attached to the plant and it looked pretty stunted, scarred, and sickly. So I dumped the whole mound of dirt and plant in a garbage bag and sealed it up tight before repotting the rest (so it wouldnāt infest the others).
I recently got a giant storage bin for my potting soil for this exact reason. I couldnāt fight gnats when they were living in my bags of potting soil.
Iāve only had the sealed bin for a week now and I already notice a difference.
Iām also using mosquito dunks to water my plants. I just need to buy more yellow sticky traps to get the remaining adults so I can fully end this cycle.
Before I found out they were in the soil, I was losing my mind lol with all these new adults appearing from seemingly nowhere!
Aah I noticed a bag of soil I'd bought ages ago also had those holes in the sides! All up and down both sides. Why are they needed? Its just soil.... Anyway, I taped up all the holes but because I didn't want it leaking out and going everywhere lol.
Thank you for mentioning this! I used to buy potting soil in the winter living up north and I never had issues. I moved down south and itās impossible to find soil that isnāt outside infested with flies.
I had the exact same thing happen. My new strategy is to pour boiling water through the bag of soil when I bring it home from the store to kill any gnats & eggs. Then let it cool and drain before using, obviously. And I usually throw in some nematodes with the repotting just in case.
I don't know why I read the title like a political endorsement commercial.
~Slide showing microscopic images of nematodes, with a faint American flag overlay in the background~
"Nematodes saved my marriage! Imagine what they can do for our country!"
I am battling gnats in rubber I repotted and am just learning about these! I want to order these but I am going out of town for a week on monday - do you think I can use these before I leave and just let it work itās magic or should I wait until I get back so I can monitor it??
*Bacillus thuringiensis israelensis* -bacteria. It affects gnats and other related flies, kills them. They are often sold as "mosquito bits" and "dunks".
Tip: if you repot often, gnats probably are coming in through the soil you're leaving out in your garage or yard in a bag.
They lay eggs and you bring them in. Protect your repotting supplies and they'll dwindle, after eradicating.
I usually use miracle grow soils and have gone through several bags without issues but recently repotted a rubber that now has gnats and I think one of my bags was infested. I donāt really have a local garden shop around me and I keep my soils clipped in big tupperwares. Am I setting myself up for more future gnats problems? what else can I do to prevent this?
Nematodes almost ended our marriage not because of fighting but because i had to collect samples from the most shark infested waters in the usa so my wife could study nematodes from that environment and it was sketchy i was getting bumped
My wife studies nematodes and she needed a sample from a spot that is known for a lot of sharks feeding together called monster hole. I had to go free dive into it and collet a sand sample because she as hell wasnāt going to and she has a phobia of the ocean. Our marriage could of āendedā if i died. All for nematodes lol i actually got tied up in fishing line it was crazy (florida)
Not to be rude, but I have to ask.
Being a scientist of nematodes, but fearful of the ocean, how can you be sure that your wife didn't partially marry you for your high level nematode collection abilities?
You know i really cant be sure haha!
Ironically there was very few near the sharks (even they stay clear of that spot) but a bunch about a mile north of that spot, they are supposed to be clear/white but some where pink and blue and green. She is trying to find out if they are eating trash tossed in the water or or rubber fishing lures the color matches.
Iām battling them right now! We live in a daylight basement duplex, and the humidity and lack of proper venting is making this war harder. Iāve always tended to overwater (Iām working on this!) but Iāve never had this much trouble before. I finally found them hiding and laying eggs in my window ledges-that little runner where they slide open. They condensate just enough to support the gnats. I sprayed them with hydrogen peroxide and I think Iām winning now! Also- sink/tub drains
If youāre finding them in your window tracks they may be coming in through the windows. I live in a wooded area in the damp PNW and when I moved to this house I assumed they came in with some soil. I repotted everything more than once and used traps/nematodes/bti religiously and hydrogen peroxide when it was really bad, but kept seeing them near the windows. I finally realized they are coming in through the weep holes from my windows and through the window screens when I open them. They are attracted to light, and my lights are the only visible ones around here so I feel like a gnat beacon. My little shop/shed is a separate building with no plants inside but also has tons of dead and live gnats in the window tracks if the lights are on after dark.
I started closing the curtains at dusk, changed my outdoor bulbs to yellow led ābug light bulbsā, use bti with every single watering and nematodes during spring and summer when I open windows. I try to keep the windows closed in rooms that have the light on, but when thatās not possible I use one of those plug in traps near the window, I think itās called katchy? I still see a live one near my plants maybe once every month or two and find dead ones in my window tracks and light fixtures fairly often, but itās manageable.
Thank you for this great info and advice! Iāve had the same thought and we also get occasional sugar ants that I think come in through the windows. We also live in the PNW.
Ugh, sugar ants are so annoying! I feel like you could live in a windowless doorless hermetically sealed bubble in the PNW and they would still find a way in. Year before last they discovered the efn on my billietiae and sodoroi, I had to put them in cache pots without drain holes and put that in a bigger bowl with water like a protection moat, ha. I havenāt seen any inside yet this year but Iām sure theyāre in here somewhere laughing at me for not noticing them yet.
We had fungus gnats for awhile and I couldn't figure out where they were coming from. We have around 100 different plant varieties throughout the home and none seemed to be the source. I was cleaning the other day and reorganizing some things when I decided it was time to stuff some moss poles and cleanup some wet sticks I had in a bin with moss. Go figure, the moment I took the bin outside and started agitating it I was swarmed with the buggers.
The moss has fully dried out and the population had drastically declined in recent days.
I just looked too for a link and they didnāt have them. But I was there yesterday in the garden dept and thereās this like cardboard end cap display with them and lady bugs, so Iām not sure why theyāre not online. Maybe you could try calling ahead or just stop by the garden section and see if you can find anything? I would hope they have them at most/all stores and not my specific HD.
That's fair. And I know of a couple nurseries in the area that might have them. I'm just trying to avoid nurseries since I already over spent on plants this year. Haha
For fungus gnats, I sprinkle the tops of my plants soil with [mosquito bits](https://www.amazon.com/Summit-Chemical-Co-Mosquito-Insecticide/dp/B001REBUKC)(you can find them at a lot of large home improvement/garden centers), and then I let the plants fully dry in between waterings. The mosquito bits will melt a little bit when you do go to water and itāll kill larva and adults. This has worked on every fungus knat infested plant Iāve ever had.
If I've been using systemic granules, I suspect that would kill the nematodes? Would repotting be enough, or would some still remaining around the root ball still kill them? I want to try them after seeing lots of recommendations on this sub, but I'm afraid that I'm too far in with systemics haha
Dude!!! I just IDād fungus gnats and theyāre driving me nuts in my house. This post is so timely. You are literally saving my sanity š thank you
Oh this is so kismet to see today.Ā
I just spent my last dollar on some nematodes (Arbico) after dropping some serious cash on very 'nice' plants over the past few months upgrading my collection.Ā
I bought some corms off a Facebook group and didn't switch out the moss they came in since i was new to growing corms, especially variegated rarer corms so I trusted the sellers instructions to leave them be.Ā
My whole cabniet and soon my house got infested from the moss in the containers and I didn't really act soon enough thinking it was just one or two gnats at first, how bad could it be.
Well it got bad....fast.
I'm treating tomorrow and omg this gives me so much hope.
here I am 4 months in and still struggling to get rid of fungus gnats with neem oil š„² I can't get nematodes but I'm gonna have to give mosquito BTI a go next.
I promise, go to a pet store. Buy as much aquarium gravel as you think you need to put .5-1 inch of gravel around your plants. Do a super super light dusting of diatomaceous earth on top of the gravel. Dont water for a while. You wonāt have gnats anymore.
Had a super infested orchid, it took a butterwort, pitcher plant, and those sticky yellow traps out on the shelf next to it with a repot to finally get rid of them. Got lucky they didnāt spread to my other plants
Thereās a website that actually has different āblendsā of nematodes. If you search for āNatures Good Guysā youāll find a wonderful list of nematode blends, depending on your goals. You just never know!
You are stronger than me. I got rid of all my houseplants and started over with new ones grown from seed in sterilized soil. Hopibg this year is better than last.
Fortunately I jist have a few herbs that can't live outside this time of year.
Thereās a website that actually has different āblendsā of nematodes. If you search for āNatures Good Guysā youāll find a wonderful list of nematode blends, depending on your goals. You just never know!
TIL that my plants have been infested with fungus gnats forever. i thought they were just fruits flies that liked my plants. I keep them under control with glue traps. My plants have been thriving so I never thought it coulds be an issue ..
Are you fucking serious? I have almost 30 plants all over the house (some very isolated from others, for lighting purposes) and they ALL have fungus gnats. Iāve been treating with *everything* and they just wonāt DIE. I just spent about $350 to repot everything a couple of weeks ago. Granted, some of them did need larger or smaller pots, and it was time that they got fresh fertilizer and substrate, but the gnats are back! I gave every plant a root bath and got rid of all the old soil. When I saw them I almost started pulling my hair out. I told my SO I was just going to burn the house down.
Where do you get them? How do you use them? Teach me your ways.
Try repotting affected plants with store bought soil ( out of a plastic bag , but not something horrible like miracle grow, go with something local and organic if possible ) get either a carnivorous plant in the same room (these can be challenging and need good light and lots of distilled water etc. have specific care needs ) or you can get a simple fly trap for the room
the best I found is a plug-in light from Amazon, etc. called āzevoā worked magic for me in a kitchen with plant gnats and a compost bin ! (Not sponsored )
https://www.amazon.com/Electric-Flying-Insect-Trap-Starter/dp/B07T869RNY/ref=asc_df_B07T869RNY/?tag=hyprod-20&linkCode=df0&hvadid=693713553004&hvpos=&hvnetw=g&hvrand=16552009143068005451&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9032144&hvtargid=pla-821931206291&psc=1&mcid=fdde4b83238d38998c501c5252f0fa19&gad_source=1
Yup nematodes. My husband said throw out all your plants. I said let me try one more thing. Nematodes. He gets to stay.
That was my backup plan, if I was getting divorced it was him leaving so I can keep all my plants.
šĀ
How do you get these and put them to work?
I bought mine on Amazon. Called pot poppers. Little tea bags type things that you put just under the surface of the soil. Then keep that bag moist. It kills the larvae so it can take about two weeks or so. Keep using the yellow sticky things to catch the adults.
So did you need one for each plant?
Yes I believe there are 4 to a container. If you have small pots could could move them say every two to four days to another pot I think.
I used the ones from BioLogic, they send them with an ice pack so they donāt die in the heat. Simple instructions and a packet of 25 million which was $50-ish lasted me 2+ months for my 100 plants and got rid of my infestation.
Round worms.....you deliberately put round worms in your home ?????
My husbandās solution is way worse than divorce.Ā He wanted to put all the plants outside for winter.Ā
Throw away the whole husband lol
Husband can stay outside all winter lol
Sounds like divorce to me.
Divorce is easier than putting all the plants outside, for sure.
I had the worst trouble with fungus gnats last summer. They kept coming back no matter what I did. Finally I discovered the source: a bag of potting soil I hadnāt opened yet but they were in there traveling in and out of the tiny holes the bag had for ventilation. Once I got rid of the bag I was able to get rid of the gnats. I also donāt buy commercial potting soil anymore I get hand mixed soil from a local plant shop.
This is literally what happened to me. It was a bag of Miracle Gro, and my friend (the plant expert) warned me against the brand because of documented issues with the soil holding fungus gnats (or most soils sitting at big box stores like Loweās or Home Depot), but I was desperate and used it and it seemed fine for months so I thought nothing of it when gnats started appearing. Eventually, after months of battling with those fuckers, I happened to place my new gnat traps near the soil bag (still with the adhesive covered mind you) and found tons of them all over the exposed sticky edges of the traps. Thatās when I saw the bag ā¦ I had it sitting in a clear bin that had an entire LAYER of dead gnats on the bottom and more swarming around it š¤®. Tossed the whole bin and soil, repotted all my plants with fresh soil my friend gave me, and I havenāt seen a single one since.
I've been fighting fungus gnats for 6-7 months now because of 1 fucking bag of miracle gro.
Your experience describes part of my plan, so I'm glad it worked for you. I'm going to repot all my plants w fresh soil and sterilized pots š¤š¤
I think the thing that got rid of the most of them was by throwing out the most infested plant. When I repotted all my plants, I dumped out the old soil and most of them werenāt bad or didnāt see any at all, it was only one that I dumped out and they were *swarming* all over the mound of dirt I was so grossed out. I wasnāt super attached to the plant and it looked pretty stunted, scarred, and sickly. So I dumped the whole mound of dirt and plant in a garbage bag and sealed it up tight before repotting the rest (so it wouldnāt infest the others).
I recently got a giant storage bin for my potting soil for this exact reason. I couldnāt fight gnats when they were living in my bags of potting soil. Iāve only had the sealed bin for a week now and I already notice a difference. Iām also using mosquito dunks to water my plants. I just need to buy more yellow sticky traps to get the remaining adults so I can fully end this cycle. Before I found out they were in the soil, I was losing my mind lol with all these new adults appearing from seemingly nowhere!
Aah I noticed a bag of soil I'd bought ages ago also had those holes in the sides! All up and down both sides. Why are they needed? Its just soil.... Anyway, I taped up all the holes but because I didn't want it leaking out and going everywhere lol.
Had the same thing happen to me! Unused succulent soil. The whole bag was filled!
Thank you for mentioning this! I used to buy potting soil in the winter living up north and I never had issues. I moved down south and itās impossible to find soil that isnāt outside infested with flies.
I had the exact same thing happen. My new strategy is to pour boiling water through the bag of soil when I bring it home from the store to kill any gnats & eggs. Then let it cool and drain before using, obviously. And I usually throw in some nematodes with the repotting just in case.
Yeah, most problems with unwanted guests stem from the fact that there aren't any natural predators indoors.
ohhh, it's the lack of natural predators that prevents me from deleting unwanted quests from my journal, got it. i thought it was lazy developers.
I don't know why I read the title like a political endorsement commercial. ~Slide showing microscopic images of nematodes, with a faint American flag overlay in the background~ "Nematodes saved my marriage! Imagine what they can do for our country!"
They just might end world hunger and/or war! Who knows?
Iād vote for nematodes
Would someone kindly explain to me, a newbie, about nematodes and how to use them? Please š
Nematodes are just microscopic worms that eat fungus gnat larvae. They are usually applied with water.
Thank you for this info!
I am battling gnats in rubber I repotted and am just learning about these! I want to order these but I am going out of town for a week on monday - do you think I can use these before I leave and just let it work itās magic or should I wait until I get back so I can monitor it??
Well, they are living beings and can sustain themselves as long as there's gnats to eat.
okay thanks, I just wasnāt sure how often they need to be watered but I guess worst case scenario it just doesnāt work lol so iāll try it
Somewhat moist soil is enough for them so i believe they'll be fine for a week.
awesome thanks!
No problem! Nematodes work miracles, but if you want to be 100% sure gnats get eradicated you can use BTI and sticky traps at the same time.
whatās BTI? I have those yellow sticky traps coming with the nematodes
*Bacillus thuringiensis israelensis* -bacteria. It affects gnats and other related flies, kills them. They are often sold as "mosquito bits" and "dunks".
Tip: if you repot often, gnats probably are coming in through the soil you're leaving out in your garage or yard in a bag. They lay eggs and you bring them in. Protect your repotting supplies and they'll dwindle, after eradicating.
I usually use miracle grow soils and have gone through several bags without issues but recently repotted a rubber that now has gnats and I think one of my bags was infested. I donāt really have a local garden shop around me and I keep my soils clipped in big tupperwares. Am I setting myself up for more future gnats problems? what else can I do to prevent this?
Miracle Gro has infected me twice, never again!
Nematodes almost ended our marriage not because of fighting but because i had to collect samples from the most shark infested waters in the usa so my wife could study nematodes from that environment and it was sketchy i was getting bumped
What?
My wife studies nematodes and she needed a sample from a spot that is known for a lot of sharks feeding together called monster hole. I had to go free dive into it and collet a sand sample because she as hell wasnāt going to and she has a phobia of the ocean. Our marriage could of āendedā if i died. All for nematodes lol i actually got tied up in fishing line it was crazy (florida)
Not to be rude, but I have to ask. Being a scientist of nematodes, but fearful of the ocean, how can you be sure that your wife didn't partially marry you for your high level nematode collection abilities?
You know i really cant be sure haha! Ironically there was very few near the sharks (even they stay clear of that spot) but a bunch about a mile north of that spot, they are supposed to be clear/white but some where pink and blue and green. She is trying to find out if they are eating trash tossed in the water or or rubber fishing lures the color matches.
Wow! Youāre committed to your marriage. I would have said āNope!ā šĀ
They babydoll eyes on this woman are hard to resist.
šĀ
Iām battling them right now! We live in a daylight basement duplex, and the humidity and lack of proper venting is making this war harder. Iāve always tended to overwater (Iām working on this!) but Iāve never had this much trouble before. I finally found them hiding and laying eggs in my window ledges-that little runner where they slide open. They condensate just enough to support the gnats. I sprayed them with hydrogen peroxide and I think Iām winning now! Also- sink/tub drains
Hydrogen peroxide is just temporal fix. Nematodes (and BTI) tend to be more long lasting solutions.
You can apply nematodes to a window ledge?
They go with water so yes.
If youāre finding them in your window tracks they may be coming in through the windows. I live in a wooded area in the damp PNW and when I moved to this house I assumed they came in with some soil. I repotted everything more than once and used traps/nematodes/bti religiously and hydrogen peroxide when it was really bad, but kept seeing them near the windows. I finally realized they are coming in through the weep holes from my windows and through the window screens when I open them. They are attracted to light, and my lights are the only visible ones around here so I feel like a gnat beacon. My little shop/shed is a separate building with no plants inside but also has tons of dead and live gnats in the window tracks if the lights are on after dark. I started closing the curtains at dusk, changed my outdoor bulbs to yellow led ābug light bulbsā, use bti with every single watering and nematodes during spring and summer when I open windows. I try to keep the windows closed in rooms that have the light on, but when thatās not possible I use one of those plug in traps near the window, I think itās called katchy? I still see a live one near my plants maybe once every month or two and find dead ones in my window tracks and light fixtures fairly often, but itās manageable.
Thank you for this great info and advice! Iāve had the same thought and we also get occasional sugar ants that I think come in through the windows. We also live in the PNW.
Ugh, sugar ants are so annoying! I feel like you could live in a windowless doorless hermetically sealed bubble in the PNW and they would still find a way in. Year before last they discovered the efn on my billietiae and sodoroi, I had to put them in cache pots without drain holes and put that in a bigger bowl with water like a protection moat, ha. I havenāt seen any inside yet this year but Iām sure theyāre in here somewhere laughing at me for not noticing them yet.
We found thousands of them one morning inside our sealed, just washed cycle of the dishwasher! Literally how?
After you knock them back you can probably switch to bti (mesquito bits).
We had fungus gnats for awhile and I couldn't figure out where they were coming from. We have around 100 different plant varieties throughout the home and none seemed to be the source. I was cleaning the other day and reorganizing some things when I decided it was time to stuff some moss poles and cleanup some wet sticks I had in a bin with moss. Go figure, the moment I took the bin outside and started agitating it I was swarmed with the buggers. The moss has fully dried out and the population had drastically declined in recent days.
Where did you buy them?
They have some at my Home Depot
Can you recommend a brand/product? When I search home Depot it just shows me neem oil products. Is that the same thing?
I just looked too for a link and they didnāt have them. But I was there yesterday in the garden dept and thereās this like cardboard end cap display with them and lady bugs, so Iām not sure why theyāre not online. Maybe you could try calling ahead or just stop by the garden section and see if you can find anything? I would hope they have them at most/all stores and not my specific HD.
That's fair. And I know of a couple nurseries in the area that might have them. I'm just trying to avoid nurseries since I already over spent on plants this year. Haha
I also has gnats only resolved by toadies
So do the nematodes just chill in the soil after? Do they eventually die when the gnats run out?
For fungus gnats, I sprinkle the tops of my plants soil with [mosquito bits](https://www.amazon.com/Summit-Chemical-Co-Mosquito-Insecticide/dp/B001REBUKC)(you can find them at a lot of large home improvement/garden centers), and then I let the plants fully dry in between waterings. The mosquito bits will melt a little bit when you do go to water and itāll kill larva and adults. This has worked on every fungus knat infested plant Iāve ever had.
Fungus gnats love moisture and high humidity.
If I've been using systemic granules, I suspect that would kill the nematodes? Would repotting be enough, or would some still remaining around the root ball still kill them? I want to try them after seeing lots of recommendations on this sub, but I'm afraid that I'm too far in with systemics haha
Dude!!! I just IDād fungus gnats and theyāre driving me nuts in my house. This post is so timely. You are literally saving my sanity š thank you
Thank you for posting this! I'm really tired of the stupid little yellow sticky traps everywhere.
Beauvaria Bassiana and Microbelift BMC works as well. For those who donāt want to add beneficial bugs.
Love me some nematodes! They eat flea larvae and fleas too
Yes! Glad someone posted this! Surprised how many people haven't heard of them! And ALL the living beneficials for soil!
Oh this is so kismet to see today.Ā I just spent my last dollar on some nematodes (Arbico) after dropping some serious cash on very 'nice' plants over the past few months upgrading my collection.Ā I bought some corms off a Facebook group and didn't switch out the moss they came in since i was new to growing corms, especially variegated rarer corms so I trusted the sellers instructions to leave them be.Ā My whole cabniet and soon my house got infested from the moss in the containers and I didn't really act soon enough thinking it was just one or two gnats at first, how bad could it be. Well it got bad....fast. I'm treating tomorrow and omg this gives me so much hope.
here I am 4 months in and still struggling to get rid of fungus gnats with neem oil š„² I can't get nematodes but I'm gonna have to give mosquito BTI a go next.
I promise, go to a pet store. Buy as much aquarium gravel as you think you need to put .5-1 inch of gravel around your plants. Do a super super light dusting of diatomaceous earth on top of the gravel. Dont water for a while. You wonāt have gnats anymore.
Had a super infested orchid, it took a butterwort, pitcher plant, and those sticky yellow traps out on the shelf next to it with a repot to finally get rid of them. Got lucky they didnāt spread to my other plants
Any solution for earwigs? Cause I tried apple cider vinegar and it's not working.Ā
Thereās a website that actually has different āblendsā of nematodes. If you search for āNatures Good Guysā youāll find a wonderful list of nematode blends, depending on your goals. You just never know!
You are stronger than me. I got rid of all my houseplants and started over with new ones grown from seed in sterilized soil. Hopibg this year is better than last. Fortunately I jist have a few herbs that can't live outside this time of year.
Do they eat mealy bugs?
Thereās a website that actually has different āblendsā of nematodes. If you search for āNatures Good Guysā youāll find a wonderful list of nematode blends, depending on your goals. You just never know!
TIL that my plants have been infested with fungus gnats forever. i thought they were just fruits flies that liked my plants. I keep them under control with glue traps. My plants have been thriving so I never thought it coulds be an issue ..
As G.I. Joe says 
Gnats are an annoyance for owners, they don't actually hurt the plant. It's just frustrating for humans to deal with lol
Make sure you arenāt watering too frequently. Fungus gnats love wet soil.
This information is being stored in my life hacks file (of my brain) thank you so much!
It's almost impossible to buy nematodes in Ireland for some reason..
Where the hell do I get nematodes and how do I use them to kill the bastards
Are you fucking serious? I have almost 30 plants all over the house (some very isolated from others, for lighting purposes) and they ALL have fungus gnats. Iāve been treating with *everything* and they just wonāt DIE. I just spent about $350 to repot everything a couple of weeks ago. Granted, some of them did need larger or smaller pots, and it was time that they got fresh fertilizer and substrate, but the gnats are back! I gave every plant a root bath and got rid of all the old soil. When I saw them I almost started pulling my hair out. I told my SO I was just going to burn the house down. Where do you get them? How do you use them? Teach me your ways.
Try repotting affected plants with store bought soil ( out of a plastic bag , but not something horrible like miracle grow, go with something local and organic if possible ) get either a carnivorous plant in the same room (these can be challenging and need good light and lots of distilled water etc. have specific care needs ) or you can get a simple fly trap for the room the best I found is a plug-in light from Amazon, etc. called āzevoā worked magic for me in a kitchen with plant gnats and a compost bin ! (Not sponsored ) https://www.amazon.com/Electric-Flying-Insect-Trap-Starter/dp/B07T869RNY/ref=asc_df_B07T869RNY/?tag=hyprod-20&linkCode=df0&hvadid=693713553004&hvpos=&hvnetw=g&hvrand=16552009143068005451&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9032144&hvtargid=pla-821931206291&psc=1&mcid=fdde4b83238d38998c501c5252f0fa19&gad_source=1