I can personally vouch for gnat nix. I've been battling them off & on. As long as you don't let them get out of control there easy to get rid of. I've found a multi-approach works best using something on the top as a dressing, gnatrol & sticky traps/a neem oil spray.
I personally think that gnat nix is the most effective. It's like sand, but made from recycled glass. It stays in place very well, is easy to water with, & works very efficiently. Just make sure to cover the drain holes as well or the little fuckers will just fly down there. Best of luck bro!
oh & also, a glass of red wine will attract them and works well as a trap. Satisfying to see them dive in & die!
ive also tried de powder which seems to work pretty well, but makes it a pain in the ass to water. I am going to start using it as a prevenative buried 1/2" under the top layer of soil. I also helps to have it sprinkled on the floor & in entry ways. When they try to hop from plant to plant it cuts them up & you get I watch them die!!
one thing iI've heard but have never tried is cutting a potatoes slice & putting it on the soil. The larvae will attach & feed to it. You can then through it out every 24-48hrs (cant remember exactly)
