Begining of Def / Tox / Bugs? and HEAT question!

These 2 plants were planted at the same time, I used the same everything for both plants. Both bagseed, and as you can see, one of the plants is wayyy bigger / taller. I'm running a T5 HO 2ft 4 Bulb, all 6500k, about 10k lumens, and will be adding 2 23w 5000k CFLs. I have a humidifier running on low, RH is about 50% at all times, 60% if I close up the closet. I run a small fan blowing on the lights, and temps run 68-75 during dark hours, 78-86 during light hours. I've made many attempts to lower temps with my setup, and with what I have right now I've done the best I can so I'm basically at the mercy of the ambient temps of the day.

On the pics below, does like look like early signs of burn or deficiencies? Or maybe bugs? I inspect my plants 2+ times daily and have never found a bug on them. I do have small fly / nats flying around RARELY, and most of the time they get in there from me opening the closet and most of the time I won't close back up until I get it out I thought maybe this way just because of natural deformities because I don't have any of these spots on the taller plant.

Second question is, the leaves on the taller plant are curling up, (the edges) I'm pretty sure this is from heat. I've raised the light to about 3.5" away from the tall plant and about 4-5" from the smaller to encourage stretching. Are 78-85 degree temps going to do this? Still seems decently cool, and my RH isn't a huge problem with the humidifier. I mist plants once a day as well. My watering schedule is basically every other day. Sometimes I wait 2.5 days if soil is still moist.

Does anything think the smaller plant is growing so slow because it's root bound? It's like a full leaf set behind and way behind in length. I've noticed to pot feels heavier than the taller, bigger plant... Why is that??

I've posted a picture of the taller plants' stems. I've noticed purplish red spots on the top-sides of the stems. I've worse on some and non existent on others. I also see it on the smaller plant but not as much.

HELP WOULD BE MUCH APPRECIATED!!!

Overwatering. No question.

Buy a moisture meter if you have ten bucks, well worth the price. If the soil is being watered too much and too often, thats what the leaves look like.

Take a look, copy, paste, print, save to archives etc. Now you know!

The stem color is genetics.

The spots on the leaves? I can't tell you for sure, could be alot of different kinds of burn yet, esp with the frequent mistings. Don't want you to cure something that isn't there and hurt yer babiez. Check the sticky in the bugs subforum and keep a eye for damage from thrips.

Good luck

Oh, and your temps are fine. Lil cooler during the day would be better, but if you can't get er done don't freak out.

That definitely could be it. I try not to water too much but I probably could back off a little bit. I'll try watering every 3 days instead, because the T5 isn't really heating up enough to parch the soil... Wouldn't over watering cause discoloration, or stunted growth? The tall plant that has the curling leaves, has been growing great. It's only 18 days old. Should they be bigger at this stage given the light I'm using?

Do you see anything wrong with the smaller plant? I was going to transplant them to their final pots (I started as seedlings in these) at 3 weeks but I might do it this weekend instead if you think she's possibly root bound.