having the same issue but mine are 4 weeks old, feed them tiger bloom ff and open sesame ff last week, im also doing 12/12 had one week veg planted them kept them on 24 hrs light then 18/6 one night then right to 12/12 .. so im in the third week of the 12/12.... just have one plant that is really green like ungoldly green .. well all of a sudden the second set of leaves are turning yellow, the intial leaves wilted and fell off last week .. four nodes high and the bottom ones are turnig yellow, but there not wilting or drying up just yellow idk .. oh and my nutes are at1/4 strength.. any guidance