issue Bacterial Spot, Burn, Light Burn or something else?

[darkchile]

The past few days I noticed a change on some of the leaves on my seedlings. I noticed they had this darker brown/yellow/black type thing on leaves going on, near the ends of each leave. Seems to go through all the way through leave. I trimmed off those leaves and separated tehe seedlings from the rest for now to see what happens.
 
The seedlings are 3-4 weeks old, variable varieties, all peroxide soaked, then water soaked to speed germination, followed by heated germination. They started in miracle grow starter soil, and have been put in miracle grow potting mix and slightly bigger pots once 2nd set of full true leaves came out. I haven't fed them directly, but the potting mix does have miracle grow in it. They're bottom watered until top is damp, then remaining water drained out. They get 16 hours of light a day under grow light, and at least a few hours a day with a fan providing gentle breeze. My concern is the coloration to the edge of leaves, if it is bacterial or am I simply overthinking. I tried to get as clear of photos as I could.
 
 I'm attaching a few photos showing the spots on leaves, and also after I trimmed them off, since appears a bit more focused.
 
 

 

[CaneDog]

That looks like some relatively minor environmental issue.  It doesn't present like leaf spot.  The irregular shaping of the leaves and the "puckering" at the margins looks like incomplete leaf formation during development.  Perhaps they dried out a bit during formation or perhaps they were too wet or there was some other passing issue involving mobility of nutrients.  Your new growth that I can see looks good and the old doesn't look that bad.  I wouldn't have any significant concern from what I see and I wouldn't be doing anything other than trying to keep my environmental variables in good ranges and watching the new growth. Maybe pay particle attention to enough drying between waterings, but I don't see any proof you're not doing fine with that.
 
BTW, if you're concerned about BLS, which I'm 99.9% sure this isn't, cutting with scissors without disinfecting the blades between cuts/plants will transmit the BLS.  I'd suggest grabbing the leaf and causing it to break off closer to the plant than you're holding it. Then you can break off all the suspect leaves and just wash your hands once, afterwards.  I wouldn't be removing leaves on those, though.
 
Your plants look like they're just doing what plants sometimes do at this point.  At least to me.

 

[darkchile]

Wow, thanks a bunch for the fast response, and such an in-depth explanation. I feel like I'm going to pepper school here to learn. 
 
A bit more background on that area. The grow area is in my basement, it's in the same room as a pellet stove. The humidity is low , like 30% typically, but air temperature varies from 70-80 depending on my heat setting due to outdoor cold temps. I also have it semi enclosed on 3 sides, with mylar blankets to bounce light/heat back to plants.
 
Would using peroxide between cuts sterilize it enough or are we talking neem or sulphur or? Last fall, that habanero I fell in love with, tried to bring indoors to overwinter. An unsuspecting guest hitched a ride in....aphids. By the time I noticed it was too late to fight back. I wonder if the nutrients in soil are just too high at this early stage of seedling. They were growing and rooting so well, i didn't want them to become bound in the starter plugs. I'll have to post up some healthy images of my grows after; they're looking gorgeous.

 

[CaneDog]

You bet.  You posted good background in the first post and it sounds even more after your more recent one that you have a good setup and you're doing the right things with them.  Maybe it was around the time of transplant that they were affected. Bottom line, I think they're fine, but there's no indication you won't have plenty of time for minor adjustments, if needed.
 
I use isopropyl alcohol because it's easy and I feel comfortable it works quickly.  H2O2 might work fine, but I don't know the required exposure time.
 
Good luck and definitely post those pics as your grow continues!

 

[darkchile]

I posted up a little Grow Log start now too. http://thehotpepper.com/topic/73278-my-zone-6a-ct-1st-time-growing-from-seed/ You kind of start to feel attached to them, why I was so concerned about anything spreading; but if the likelihood is less then I'll be less concerned.
 
I think I'll end up having too many plants by spring time and have to give some of my grows away.
 
I have a few bottles of rubbing alcohol.