End of leaf turning black

[newbiepepperguy]

I started my hot pepper seeds about 6 weeks ago now, and the plants are growing nicely. I'm on a watering schedule of about every 4 days (depends on when the soil seems overly dry and/or plants start to wilt). I watered them all last night, and this morning just one leaf of just one pepper was black and shriveled on the end. No other leaves or stems on the plant seem affected, and none of the other plants are doing anything similar. Any idea what it could be?
 
I realize it's hard to diagnose without pictures, so I'll take some when I get home, just didn't know if anything immediately jumped out at anybody based on the above information. Thanks in advance for any help

 

[moruga welder]

!  and  yes pics are nice ,  i'ma gonna take a wild guess , but probably a little to much water , Is there fresh moving air ?   

 

[newbiepepperguy]

Thanks!
 
Yes, the plants are in the basement, but they are by a door and below an air vent, so airflow shouldn't be an issue, I don't think. That said, I'm not entirely sure how much airflow is required. Should I have a fan dedicated to just the plants, or is the moving air from the door opening a few times a day and from the vent throughout the day enough? As I type, it does occur to me that this plant is in the middle of the tray (4 inch pots in 1020 trays), and has 2 of the taller adolescent plants right next to it, so maybe you're on to something. How long should I leave the fan on if that's the fix?

 

[moruga welder]

i got a 6" that runs the whole time the lights are on , just below the lights , then i run a 16 " oscilating fan on them for about 15 min. couple times a day . sturdys them up as well . 
Hope this helps 

 

[newbiepepperguy]

Here's a picture. Seems that in my early morning stupor yesterday, it seemed worse than it is, as that's not close to black. Still, should I be concerned? For the time being, since it was a lower leaf anyway, I cut it off just to be safe.
 
http://imgur.com/a/v3yFK

 

[The_NorthEast_ChileMan]

Potting media looks very wet.....
 

I'm on a watering schedule of about every 4 days (depends on when the soil seems overly dry and/or plants start to wilt). I watered them all last night, and this morning just one leaf of just one pepper was black and shriveled on the end.

Ooopps, sorry! Here's the pic if that helps you!