Brown spots on one plant -deficiency? bugs?

I have a small outside grow going in a greenhouse. I think they all might have developed a slight N deficiency (see pic with yellow leaf), only one of them is turning brown on the inside leaves. Many of the leaves also have a brownish liquid on them also. I did spray it down with a diluted neem solution a few weeks ago about the same color, but I wouldn't think it would still be wet if that was it.

I can't find any bugs on the plants, so really starting to wonder what this could be. Hopefully I'll figure it out before the whole plant starts to go! Any ideas?


Outdoor (greenhouse)
Soil
Mix of black gold/Nature's Best potting soil
Compost Tea
Hose water
Water ph: 6
3 months old
green house window and door open for ventilation

Could be a grasshopper in there somewhere. That's what I had in my greenhouse.

Interesting on the shiny stuff. Reminds me of slug residue up this way in the back yard.

My thoughts on the brown spots is nute burn, but the garden looks pretty good in general. Can you fill out the troubleshooting form, got a linkbelow? That will help folks a little more.

Looks like a bird took a dump on the one leaf, or something splashed on it and that is the residue.

Looks to me like nutrient burn, or possible leaf-edge irritation.
When two or more leaves rub against each other, they can do damage to each other, and can look like that. And since the rest of the leaves in the other shots don't show this symptom, doubtful it's from applying nutrients, unless they were splashed-on and left to burn. (localized to the group that was splashed)

Also, looks like a slight ph issue.