First post/first grow - help please!

[Elamigo]

I am now at 5 weeks of veg time looking to start flowering soon, but I wanted to get some opinions on a few problems I've been having before I make the switch. I'm growing 3 plants in FFOF with the bottom 3rd of the pot containing Vermifire (recommended by my local hydro shop owner as a replacement for TGA super soil since they recently ran out.) My other 3 are in roots organic with the bottom 3rd Vermifire. All are under 1000w air cooled lighting with a couple smaller fans circulating air in the closet. Here's a few chronological pictures of the plants development the last week or two.

Last picture was taken today. Seems like most of the problems started after the first feeding so last watering I just gave them plain water. Here's a few close ups of the problems that have been worrying me.

Darkening leaves and generally twisty new growth on this DNA Sharksbreath. I assume the dark leaves are nitrogen toxicity but the plant hasn't shown much signs of improvement.

Lower leaves are curling downwards pretty heavily on this hortilab starbud, I'm stumped as to what this is.

Another DNA Sharksbreath that I've been LSTing, some discoloration in the leaves and some old heat stress that I've since corrected. My temps were in the mid 80s and after dimming my 1000w MH to 75% they hang in the high 70s now, I'm assuming the loss in lumens is worth the stable temps.
So here are my main questions:
1) anything I can do to fix/prevent these problems from getting worse? I wanted to flip to 12/12 in about 5 days.
2) my soil tends to take 7-9 days to fully dry in 7gal smart pots. Is this too long, and if so is there anything I can do to improve drainage?
3) at the moment I'm just leaving my closet door open day and night for air circulation. When I switch to flowering this could become a problem for light leaks and I was wondering if it would be a bad idea to just shut the door on them during their dark period for total darkness. I could leave a small fan on in the closet to circulate air.
I've been browsing these forums for a very long time and am only now starting to post for the sake of my plants. Thanks in advance for any advice, I know I'm asking a lot of questions but all help is appreciated.

 

[Elamigo]

Nobody has any advice? Really need some help here I don't want to cause any problems in flowering from my ignorance

 

[Weaselcracker]

People will chime in eventually. I don't feel expert enough on your plant problem to really go too far out on a limb because I know someone else can glance at them and know what the problem is right away. It would seem like your soil has a lot of nitrogen in it still, from the dark green, so it would seem to make sense to try to veg longer to use more of that up before flowering. Any possible heat stress maybe on those burnt, cupped looking leaves? I think your plant will be fine if you can not overwater and let them grow longer to burn up all the fertilizer.
Yes that is taking too long to dry up between waterings. A tricky plant/pot size ratio. When the plants get bigger it will work out much better. I aim for about 5 days between waterings. So when you water, give them less for now, veg longer so they get a bigger and better root system to deal with all that soil.
Ideally you would have vent fans there hooked to a thermostat, to bring in fresh cooling air while the lights are on. My vent fans don't run during lights off because the temps drop a bit and they don't kick in. So that's fine. But watch your humidity- if it gets too high in there at night it can cause mold problems late in flowering. Movement fans help

 

[Amadeus Forzin]

Being a new grower myself I can't offer an expert opinion. It looks like a nutes deficiency in some pics and possible over watering in others. Maybe this chart will help you. Have you checked the ph, temps and rh are all OK?
Keep on growing ✌

 

[James dBong]

The last pic is nutrient burn and heat stress

 

[James dBong]

Put some fans and give less nutrients

 

[Elamigo]

I've only fed them once and that was weeks ago so I guess I just have some really hot soil. already have an inline fan venting my light and 2 smaller fans blowing in the room, the heat stress is in the past they don't get above 80 now. Right now I just have all the fans turn off at night as temps tend to drop to high 60s in the dark period. Humidity in the day is 50-55%. I don't have money to buy a ph meter or I'd be checking it. Thanks for feedback hopefully they'll start drinking more so the pots will dry out faster. For now I'll try to let them veg a little longer, but if I wait too long they'll get too big for my space. Any ideas as to when I should feed them again? Don't want to burn them like I did last time.

 

[Weaselcracker]

I would say don't feed at all until that dark green colour lightens. It might be a while. Your FFOF soil has nutrients contained in it, not sure about the 'super soil' but I wouldn't be surprised base on the name so they probably won't need nutes for a long while yet. I've never end used those types of soil. But once they stop being overwatered the plants will be able to take them up much more efficiently. Look into lst if you're running out of space or I suppose you could just go to flower if you have to- I'm not sure what would happen there- I'm sure it's been done. Plants use less water during flowering. I usually aim for a plant over 24" (untrained that is) in veg if I'm going to a 5 gallon pot and then it stretches from there

 

[Elamigo]

I've been LSTing the bottom left plant since the start, tied down the middle 2 recently to try to even my canopy and bring more light to side branches. Guess I just won't feed for a while, probably will stay away from FFOF in the future as my plants in RO are looking a lot healthier and not showing as much nitrogen toxicity. Hopefully the buds turn out alright I have no past experience so I really don't know how much these nutrient imbalances effect bud quality.