Hydrogen Peroxide?

[Oldguyrealy]

Ok problem with Fungus Gnats every so often in grow and Greenhouse.

I understand it isn't the Gnats that cause the problem.

I find that Hydrogen Peroxide will take care of the problem and plants like it.

So what about putting some around plants as more of a preventive once a month?

 

[green_machine_two9er]

Microbe lift BT would work better and be more cost effective I would think. Not sure peroxide will do anything at the soil level.

 

[Fangthane]

I've seen this recommended on this site for dealing with gnats:

Amazon.com

Pretty sure peroxide will eradicate the microbial life in the soil, so you'll probably want to reintroduce some after the gnats are gone. May want to take that into consideration if you're gonna stick with peroxide.

 

[Oldguyrealy]

What about Mosquito Bits spray?

 

[Billy the Mountain]

A BTi spray would be ineffective against fungus gnats; it needs to saturate the medium completely.
Add BTi to the nute mix to thoroughly soak the growing medium.
BTi prevents gnat larvae from developing but does nothing to adult gnats.

 

[Oldguyrealy]

A BTi spray would be ineffective against fungus gnats; it needs to saturate the medium completely.
Add BTi to the nute mix to thoroughly soak the growing medium.
BTi prevents gnat larvae from developing but does nothing to adult gnats.

Well the Larva does the damage.

 

[Billy the Mountain]

Well the Larva does the damage.

Exactly; a spray is unlikely to ever reach the larvae.
You really need to completely saturate the entire growing medium to ensure full coverage. A spray is only gonna be superficial.

 

[green_machine_two9er]

Well the Larva does the damage.

Not really. If your plants are happy then even a “large population” of fungas gnats larvae can’t do much to plant. Obviously they can chew on roots but they really only prefer organic matter that is breaking down. So if your roots are unhealthy and rotting then yes.

Otherwise just do the BTI drench.

The really danger of gnats is bugs in sticky flowers

 

[sfw1960]

What about Mosquito Bits spray?

Not sprayed here!
Just a TBS watered in the top and I only treat if I see any gnats. It's the closest thing to a pesticide we use here. Apply once and reapply in three weeks has been great for getting them under control.
I believe Summit Responsible Solutions has instructions on the package of the bits...

 

[Bud man 43]

Top with 1-2” play sand- done

 

[farmerfischer]

Mosquito dunks

 

[Oldguyrealy]

Mosquito dunks

The same as bits.

I repotted the ones I was having trouble with going to repot them again once I get the soil I want.

 

[JeffWix]

The same as bits.

I repotted the ones I was having trouble with going to repot them again once I get the soil I want.

I just used mosquito bits to help my fungus gnats problem...definately working...I use pool skimmer bags to put the bits in to soak them...I usually do 3 gallons so that is a 1/4 cup of bits...Spinosad knocked them down but not out