Gnat problem (plus pic of my first grow at 18 days)

Hey, I have noticed some fungus gnats buzzing around my plants. My real concern is the five Critical Kush and two Spiritual Punk seeds I have just put in some soil. When I researched these insects and realised they could eat the roots and kill my new seedlings, I put a fine mesh over the box the seed tray and seeds are in and sprayed a bit of watered down pyrethrum on the surface. So I guess the questions are will the gnat larvae in there die, do I need to do more, will gnats be in my rockwool, do they live in the water. I have 4, 18 day old White Widow in DWC in makeshift tent (new one coming) 400w mh, 100 litre container, 50 litres of water, Dutch Master Original A/B 50%. ph 5.9 - 6.0. Thanks in advance

i know you need to treat the colony of gnat larva. if youre just starting to notice them, they probably dont have a huge one yet. if its been awhile..you have other issues.

what soil did you use?

i would get rid of the soil while theyre young and get some other soil. not sure if they can lay eggs in those clay balls..i like the setup though, nice color on plants too, good job with solution

if you dont want to get rid of soil, i would spray for a least a week (unfortunately)

i think a layer of sand kills them naturally by suffocating them

Thanks, yeah I had problems started this lot ( a few died ) in paper towels and rockwool that's why I am started these in soil. I hope if I can kill the larvae, and no more can get in? Thanks for the kind words bro.

what soil did you use? so we know as consumers which soil comes with gnat larva.

Nah bro they are everywhere outside here, they have only gotten to the plants the last couple days. I think chasing the light.

"In greenhouse experiments, the found that Bounce dryer sheets ( Outdoor fresh scent ) did repel adult fungus gnats. It may be because the sheets contain Linalool and beta-citronellol. Linalool is found in lavender, marjoram and basil. Studies have shown that it repels mites and other insects. Beta-citronellol is found in citronella, rose geranium and lemon balm and is thought to repel mosquitoes."

Thanks, I looked at them but I can't get them where I am. But I sprayed some pyrethrum around and they are dropping dead and I will keep doing that until I get my new tent.