I think maybe you should change the irrigation cycles. Instead of 15 min 2x a day try 15 min every 2.5 to 3 hrs. Those plant are sitting in hydroton and they aren't extracting any nutrient from those rocks. They look hungry.

Good Luck Amigo
muordeeb Reviewed by muordeeb on . Help quick! seedlings brown spots! Hi, I have attached some pictures of what my seelings have started to look like in the last day. I am concerned about the slow growth and also the small brown spots on some of the leaves. Here is all the info: 400W metal hailide light approx 3' above the plants The seedlings are about 4 weeks old. They were transplanted to the hydro setup about 5 days ago. The pH has been kept at a constant 5.2 or in that close range, but when I woke up this morning it was at 7.1 Water temp is about Rating: 5