sand

hi, im having real problems with fungus gnats, senn a vid on you tube from a guy with same problem , he dug out 2-4 inch of soil and filled with sand, and used beakers with coffee in them and it attracted the flies to the coffee, has anyone tried this , and will the sand effect my plant ????? had 9 really healthy plants the other week, now one is not well at all

The sharp edges on the sand granules will cut into the little buggers and encourage them to
move on to find better nesting spots.

I dont know about the 2" depth part. Seems if you dig that deep you would cause significant root damage
to your plants.

lokie said:

The sharp edges on the sand granules will cut into the little buggers and encourage them to
move on to find better nesting spots.

I dont know about the 2" depth part. Seems if you dig that deep you would cause significant root damage
to your plants.

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that was one of my worries, might put the sand on top of the soil as it is, without digging.

I put sand on my soil to fight fungus gnats. I put half an inch to an inch of sand topped with a sprinkling of hydroton to help keep the sand in place. I only do this in flower. In veg I just use Mosquito dunks mixed in water, and also spray any buggers I see with a neem solution. It's hard to completely get rid of gnats when you grow organic is soil, but you can do a lot to control them.

i thought that too but ive got rid of mine, with the yellow hanging strips and small pieces cut and put on top of soil, it took over 6 months but eventually they were gone. Using new soil,perlite each grow also helps and always wash out pots.

*BUDS said:

i thought that too but ive got rid of mine, with the yellow hanging strips and small pieces cut and put on top of soil, it took over 6 months but eventually they were gone. Using new soil,perlite each grow also helps and always wash out pots.

Click to expand...

I think my problem is that every time they're "almost gone" I end up slacking off on my gnat battle routine, and then they come back in force. I don't really have much of an issue in flower with the sand/hydroton technique, but I really need to purge my veg tent. I just really need to get back into a very regular gnat fighting routine, and continue it for at least two weeks after the last visible gnat.

i also will do a root drench with neem oil by filling the drip trays really fast it will drown the adults and kill the larve it will soak up the neem water. the next morning lift the pot and you can see all the larve that you killed sand works thats why they live and breed through the drain holes.

Do you happen to water from the top? If yes, try watering from the bottom.

I like the sand and hydroton idea.

an update on these gnats and larve, have used the potato trick, (cut potatos up and place on top of the soil to attract larve) and the not well plant seems to be coming back to life, checked the potato pieces today and there was definetly larvfe on one piece of potato, so seems to be working, also only managed to get some normal fly sticky traps (not yellow) and have put a few on the floor (did see 2 things run across the floor, killed them with my hand) and got an old yellow sand castle bucket and stuck ply strips round it,

will keep you informed day by day as i go, ( maybe cutting them down sat), will stick some pics up tomorrow as well.

If you havent used any chemicals or pesticides to fight off gnats and you havent put any sand in your pots, look into predatory nematodes, a microscopic ring worm that will feed on the gnat larvae making the adults not want to go near the pots, catch the adults with yellow sticky pads. Plus its all natural "fight mother nature with mother nature"

I'm having this same battle. It seems like no matter what I do when i grow in soil i get an infestation of these little bastards. gonna try a few things on here and if it doesnt calm them down then i'll order some predatory mites.