I'm having difficulties getting my habanaro, banana and jalapeno peppers growing. The got about 2 ~ 4 true leaves and have stayed at that for the last 3 weeks. I don't think its a lighting issue as I have bell peppers, tomatos and cucumbers that are all doing really well under the over-driven 4 T8 lights i have there. The only thing I can think of is I used a different type of soil which is course and has larger chunks in it. It doesn't seem to retain water very well as when I poor water in it comes out the drainage holes very quickly. The leaves are beginning to turn slightly yellow and there's no new growth for the past 3 weeks.

Nitrogen levels are a bit low but nothing seriuos, phosphorous and potassium are a bit high and the PH is around 6.5.

Suggestions?