just off the top of my head I would say they appear locked out and rootbound. But with the medium you are using, I'm afraid I'm not familiar enough to say......I do not as a rule play with coco and you I'm not familiar with "light warrier" so while I strongly suspect lockout......I'm not at all sure what your ph should be.

Those are my suspicions anyway....ph lockout/and or rootbound and/or both.