General help

Hello my friend! Yeah f*ck those gnats! I hate them and also used neem to kill them. Do not give neem during flowering then you can better let them live and catch as many as you can with yellow tape. The plants are looking healthy and you just need to make sure that you give the right pH 5.8 and that you do not overfeed with autoflowers EC 1.6 is usually the max. But better give to low then to high so EC 1.2 from now will do and up with EC 0.1 every week till 1.6 do not give more. The best way to check if coco coir is dry is to lift up the pots when completely dry and when straight after watering. Then you've got an idea howmuch water is in there. When the coir is around 80% dry it is time to water again. But again looking great and they will be ok! Have fun my friend!

So it's still early but those are autos...you want to start those in a big pot usually. What I would do is get some five gallon fabric pots and fill them up with some Promix HP the cut out the bottoms of those pots and bury them about a third way into the five gallon pots. That will be your transplant without stressing them out. You really want to give autos a good.veg period and not hinder their growth, give them lots of root room. From there get some good organic nutes lime Gaia or build a soil and top dress give them a decent top dress for the coming weeks.

After reading Week 3, it seems you've already got your solution for the gnat issue, the neem oil and yellow sticky traps are exactly what you need. As far as the stress you've caused to the plant it does need time to recover but unfortunately, autos don't have the time since they are on a predetermined life cycle..

If you want Gnats gone, never to return, and to never have that problem again, then bottom water your plants. The water will wick up into the medium and distribute perfectly in your soil, while the top inch of your soil remains bone dry and uninhabitable for Gnats, they will die as will their Larva. Over watering. Funny how people think Coco can't be over watered, well it can. And especially yours if that's what your using because you have no perlite or or anything in it to given it aeration and prevent it from compacting and depriving the roots of oxygen.. Straight coco will cake if there's a lot of powdery coco in it. Your stuff looks like it came from a expanded brick. That stuff is crap and is full of sodium and Potassium and is generally poorly treated. Especially bricks off Amazon. Always pay the extra to get coco from a reputable source, like Canna or Mother Earth. They sell pre mixed and buffered coco in 50 liter bags. Already mixed with a 30% blend of perlite. and it is buffered with Calcium and the pH is stabilized to an acceptable range.

Fungus gnats I'd use some sticky traps. Either purpose bug catchers or DIY spikes and duct tape. Re light. 1200w is a lot and they don't look like they have been stretching. If the nodes are super close the back the light off. If true watts then you want over 24" away and dimmed right down till you see a bit of spacing 0.5-1" is what I like . Visually they look quite healthy. I suspect some over feeding with the tips burnt like that. I can't see your medium. If Coco flush with H2O until run off is same as going In. No ph or EC details. These metres are essential. 5.5-6.3 in Coco 6-7 in soil. The newer growth looks better so you are likely doing better all round. Keep eye on new growth Hope this helps