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Having a issue with fungus gnats?

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It got better then it got way worse.

Is it because my brother waters the plants then has the tent open for hours at night with the bright light coming out with a sliding door lending outside right by the tent? is this attracting them?

It seems it be getting worse even with neem spray its not a closed environment as my brother likes to leave the tent open and just to stare at the plants for hours not sure if this is a good idea

what you guys think?



Edited by pj3d
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What Ill_Even said, plus tell your brother to stop watering so much.
Fungus gnats love wet top soil, he needs to let the soil dry out at the top before watering again.

Yellow sticky traps are one of the best things to get ride of and prevent fungus gnats.

To get rid of the fungus gnat larvae, you can mix up a hydrogen peroxide and water to make a 1% hydrogen peroxide mix.
Pour it over the top layer of soil, you really only want it to soak in like 2cm into the soil, so don't over water as it will kill pretty much all microbes in the soil.
Do this every 2nd day for a week, then you can introduce microbes back into the top soil with any microbial blend.

I wouldn't recommend growing with the tent open and access to outdoors, it will attract everything from fungus gnats to thrips, aphids, spider-mites, etc and completely defeats the purpose of growing indoor because you are still subjecting the plants to outdoor stresses (like bugs).


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I also had a fungus gnat issue on my 1st indoor run - I switched to bottom feeding/watering to keep the topsoil dry. (plus, I could see exactly how fast my plants take up water - I still water manually, been doing it ever since.) The few bassas that get in at the start lay eggs and the larva stays in the soil until they mature and then repeat the cycle. All in all, fly traps as the guys mentioned and getting that top layer dry and after that expect to see the larvae that matured buzzing around, at this point if there are any wet soil around, they will repeat that cycle. It's a bi-atch, but winnable. :rastabanana

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Did I miss the mention if this is organic or synthetic? I can give info till I am blue in the face, I'll just leave it here, but your top soil is where your feeder roots are and the bottom soil is where the drinker roots go. a plant naturally takes more nutrients through the roots closer to the top, because that's how nature works. top soil is where decomposition happens, most life and nutrients in the top soil, so letting top soil dry out is literally just for synthetic hydro growers with inert media. not organic growers. organic growers make a unwanted situation when letting top soil dry out. that's why we use stuff like mulch or cover crops. 

hydro growers focus on the capilary action of their media, meaning if they bottom water the top should still get wet by soaking the water up all the way and they also cover the tops of their pots to avoid top transpiration so the media doesn't dry out, cause that will cause the nutrients to recrystalise and burn the roots. basically there is never a good time to let soil dry out besides when you over watered. still then you don't let it go bone dry, you let it go to about 50% and then change practice to avoid same problem. 

Organic growers soil too dry kill microbes and your primary focus in organic growing is microbes. (microbes obviously live where most microbial activity is = top soil) Synthetic growers letting their soil dry out too much risking recrystalising of nutrients. 

What helps in both situations is watering less, but more frequently. hydro situation flood and drain quicker or let the drips run for shorter time but more frequent. to me it sounds like your brother is hand watering, I do that too, I got 30L pots with mature plants in, they never get more than 500ml water per pot, but that's every day. sometimes less, but never more. Don't wanter a whole lot at once then let it sit like that for a week, that's also damaging. Big up and down fluctuations cause more bad than good, you want a consistent moisture situation in the soil. not soaking and then drying. aim for 50% moisture, keep it there. safer to go on the lower side than the higher side. 

fixing the water problem will already do a whole lot in fixing the bug issue, but won't resolve it.

Just closing the grow room will do wonders too, even besides just the bugs. You need environment to stabilise. leaving a door open too long isn't just attracting bugs. They make tents with viewing windows although I don't use mine, but it's for the purpose of not having to open the grow space when not needed. when you got work to do it's best to just open, do the work and close up. 

resolving the issue you may need to get yourself some Diatomaceous Earth and topdress with it, cause the reason why you getting those gnats is the soaked soil, but they don't come to eat the soil or just come by to "look at it for the fun of it" they come there to breed and lay eggs. so you gotta worry now about gnat larvae. the flying ones you can catch with sticky traps and some IPM, but even the DE wont help the flying buggers, but your new thing is stopping the larvae from coming out through the soil and starting a new colony. that's probably why you saw it then it got better then worse again, cause you've invited them in, probability of there being nests in your topsoil is already through the roof so yeah. I would say get sticky traps, get DE, fix your watering and keep the grow space closed. if you only half ass it you be asking the same questions next month 😉😁 

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