I think I have fungus knats which apparently come in most soils will this get rid of them?
From my understanding of DE , the ground up diatoms have very sharp edges when viewed at a microscopic level , it gets in the moving part areas of the insect and cuts them up probably desiccating them as wellâ
So woukd this stuff be OK to use? Coz the first one I ordered wonât be here for over a week the Amazon one I could get on next day delivery
D-earth is a temporary fix only - you can cover the top of the soil when itâs dry and it will kill the active ones off, but as soon as you water it stops working. Mixing it into the soil does not work.
the only thing that works for me is Bti - I use Gnatrol, not sure if you can buy it in the UK. I drench the soil with 2-3 tsp. per gallon of water, for 2 or 3 waterings, and it kills them all. Bti is in âmosquito dunksâ also, you can grind them up and stir the pieces into your water.
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Nothing off the shelf has ever helped me with fungus gnats. For me all the products iâve tried just masked the problem and never solved it. I donât use chemicals at all and tried as many natural solutions as i could. Compost tea has works best for me so many beneficial organisms including predatory nematodes. You could also see if you can order predatory nematodes.
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This pre existing thread should be helpful:
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Just ordered some mosquito dunks gonna try them mixed in with water like u mentioned 
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Nematodes have worked well for me too, but you canât store them, you have to order a new batch every time you mix soil or transplant, I wish they were an everyday item at gardening stores, itâs like $30-$40 per batch at Arbico.
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My soils contain predatory mites which will also aide in getting rid of those little mother f$&@:ers eggs!
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Here is one of threads Iâv posted in
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I am using fox farms ocean forest organic soil
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Hello gang. I moved the thread to this one, itâs been going for a while, more info on the subject for everyone. Thanks.
I bought some at the local hydro shop, and they are in the water alright, but watch out for pH, mosquito dunks raise pH like crazy, a whole lot i mean. My filtered water comes out at 6.0~6.5pH and only the BTI takes to more than 8pH. So keep an eye out for that.
I have been controlling the pH of the water before feeding but i never seen any gnats. I saw some mini-spiders today, they had little bridges between the pots, spider web bridges that is, i applied AzaMax, and that should take care of it. I guessâŚ
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Not familiar enough with fox farms soil
@lotus710 may give some valuable input with this potting soil.
Thanks for the heads up I ph my water to 6.5 so will keep it in mind did the mosquito dunks work for you?
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DE, sticky traps, neem and karanja all work well for me but you have to reapply all of them occasionally. Depending on where you live your gnats could be coming in on your clothes, through unfiltered ducts, or just flying in if you keep your door open too long. All bagged soil in the Northern California area that i have used at one time or another has had gnats in it. It is impossible for me to grow 100% of the time with out having them. I can go six months or so but one mistake or happenstance and i am battling them. I recommend sticky traps on most pots all the time, it gives you time to act when they get started. I have never used mosquito dunks but here good things about it.
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skeeter dunks crushed and top dressed or if your hydro toss it in a stocking and then in the rezâŚthen follow up with yellow sticky traps and insecticidal soapâŚgotta kill the fliers they lay 300 eggs a day. 
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Cheers guys I have sticky traps in place got some DF coming along with the mosquito dunks hopefully that will sort it
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Is there a particular insecticidal soap u would recommend
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I use rockwool an as long as you keep your cubes in the dark donât let any light hit there wonât be any algae to lay there eggs so they canât reproduce
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