HELP! Gnats! What happens if I cut down my scrog net?

Thanks for the info! So they drain tray I had them on was bright ass yellow so I had to pull that and put different trays under them. The gnats have since started going for the yellow
stickers and most of them have gone. Going to the garden store tomorrow to grab some killer for them.

You should always put large sticky traps at the base of your plants stalks. https://www.amazon.com/Catchmaster-36-Count-Monitor-Catcher/dp/B0839P1DQ8/

I get the 72 pack from Amazon and use them on EVERY plant. They pay for themselves. If you have a re-occurring problem with gnats then a sure fire solution is going to be to do a watering with Spinosad bacteria in it. Bonide makes a good one called Captain Jack's Dead Bug Brew found here: https://www.amazon.com/Bonide-252-Captain-Jacks-Concentrate/dp/B001VJBYMC

You always want to treat Gnats in waves because they have a really fast life cycle. WHat I do personally is use 2 oz per/gal of water of bonide and spray anywhere that they can breed or enter (pot holes at bottoms, top surface of potting mix, lower portion of plant & leaves).

Captain jacks will ensure you eliminate the bugs long term but the sticky traps will not only help catch fliers but it will let you see that there is a problem much easier.