Problem with Tomato

Problem with Tomato

I have a tomato plant that's been having some issues for a while now and I don't know what the problem is, if the plant is getting too much or too little water, too much or too little fertilizer. The browning on the edges of the leaves starts from the oldest leaves first, and makes the leaves curl upwards slightly. This is the oldest leaf on the plant, I had pinched off the other leaves that had already become too brown and crispy to save. I have some other seedlings that aren't having this problem, but I'd really like to save this plant.
Welcome To The Boudoir

Welcome To The Boudoir

IDs, please

IDs, please

My musings on rain barrels and catchment systems

My musings on rain barrels and catchment systems

How do I prune this?

How do I prune this?

Advice, please

Advice, please

Plant ID help

Plant ID help