Leaves yellow at tips, eventually shrivel and die.

This is my first real grow, I've helped friends in the past but nothing like this on my own.

So I started these plants from seed about a month and a half ago. I recently transplanted them into larger containers thinking perhaps they were root-bound.

It seems like a nitrogen deficiency to me, but I'd like to get a 2nd opinion. I thought perhaps it was the water I was using, so I started using reverse-osmosis/distilled water (before I was using rain-water collected for my organic vegetable garden).

What kinda soil / nutes?

Nothing special, potting soil mixed with 50% paralite and 15-10-15 nutes, diluted to about 50% the recommended strength. Might try some fish emulsion tonight see if that helps some.