Spinosad drench yay or nay?

Hey all. I seem to have a gnat problem starting in my garden. I thought I was on top of it I was giving a weekly spray of neem but didn't seem to stop the problem from occuring. I only water ever 4 days so they dont stay all that wet although I did notice some water accumulating under the tent.

I have set sticky traps up and left some potato slices to trap the larve but o also want to give the soil a nice drench to ensure these guys are gone.

Which comes to my question whether to use Spinosad or not? The label calls for 20ml per ltr. (Sounds like alot) sound right?
I also have BT.k not BT.i which I have read will do nothing to the gnats. Also mosquito dunks are not for sale in Australia in fact I'm pretty sure you can't buy BT.i here full stop.

So can I drench using Spinosad? And does a concentrate of 20ml to litre sound right. I sure as hell don't want to kill my girls.

Btw they are 5 weeks into flower so neem is out of the question.

Any input would be great

Thanks for reading.

Anybody use spinosad for gnats? Has it been effective?

I use Spinosad for thrips, not sure how well it works on gnats tho. I've always used Azamax and sticky traps for Gnat control.

Do be careful on the dosage of Spinosad, I overdosed a few plants and almost lost them. If it does happen give them a good flush.

Thanks for the reply. I read that gnat larve wont do much damage if any to mature plants . My girls are 5 weeks through flower. So I guess im still tossing up wheather to use it or not. If I do it will be at half strength.