Fresh bags of Recipe 420 have gnats - fungus gnats? - what to do?

Filling 100 gallon smart pots for outdoor grow and my bags of Recipe 420 have gnats. The reason I'm calling them gnats is they have the quality of gnats we all know from when we were kids. They are small, fly back and forth very fast, they are a light grey color. I assume these must be fungus gnats? Could they be something else. If fungus gnats this really sucks, spent a lot of money on this soil, putting all this work into this grow and I'm starting off with a gnat problem - I'm really pissed off. I understand fungus gnats can really attack the roots and I'm already dealing with a root problem from having over watered.

Anyway, my two questions are:

1. Are these definitely fungus gnats?
2. What can I do to get rid of them for good?

For one, stop freaking out over gnats.

Not only are they virtually harmless to your plants, but their presence is an indication of very healthy soil.

Getting rid of them is very simple, don't overwater, let top soil dry thoroughly, and good airflow. They'll go away on their own since they won't have a suitable environment to reproduce

1. Fruit flies or fungus gnats are the likely suspects.
2. Compost piles have these problems Google.

They are a very serious problem especially to smaller plants and/or plants that do not grow very quickly. The larvae attack the smallest sections of roots such as root hairs and new development. So if you quickly Google to see if the adults are harmful you might miss the larvae. The great news is this is a common problem for compost piles not limited to growing mj so just Google a solution you are happy with.

P.S. I just Googled there is misinformation out there saying they only attack dying plant matter. If that were true they would be a beneficial insect. Fungus gnats can kill a little plant I've seen it happen so make sure to read the sites that say "they eat root hairs".

Sticky strips ,

Water your plants from the bottom. If the top couple of inches of soil are dry, the larvae will die.
Of course outside not so easy to do. No worries, the bats will eat 'em.

Mosquito dunks AKA Gnatrol, or bacillus thuringiensis if you prefer

Are fungus gnats not much of a problem for bigger plants, like in 100 gallon pots then?

tilopa said:

Are fungus gnats not much of a problem for bigger plants, like in 100 gallon pots then?

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No, not established plants.

I like this stuff.....Water it and repeat in 5 days - twice.

Microbe-lift/BMC

Yeah not a problem for bigger plants just gnats in your face, nose and etc. If I have a severe problem such as a stall I just throw sand on top of the planter otherwise on large planters I let them dry out so much gnats can't breed effectively. If I have a problem with a mother plant in my veg room I might hit Hydrogen Peroxide just the top layers but that advice gets me yelled at by the others, so don't do that one

Dr. Who said:

No, not established plants.

I like this stuff.....Water it and repeat in 5 days - twice.

Microbe-lift/BMC

Click to expand...

Great suggestion, its my nuke of choice for gnats and every year I throw a bottle in the pond, for the most part keeps the mosquitoes away, which keeps the frogs away, which MOST IMPORTANTLY keeps the snakes away

BTI mosquito dunks
Spinosad soil drench
Promis soil drench

Pick one, and done.