I'm going to guess nutrient deficiency. I am by no means an expert on this kind of stuff - I've grown tonnes of aquatics, but terrestrials and veggies are all new to me. I know the misshappen new growth is a lack of nutrients - my guess would be one of the macros, but I'll let some of the experts chime in. I get the dried up ends on plants that are in systems that aren't fed well, or on plants that I assume don't like wet roots (though, I've since learned that almost any veggie will grow wet, given enough O2).