plants need a little stretching, your lights are a little too close. try taking pics in white light next time, not sodium. try pH at 5.8 to 6.2. I think 5.5 is too low. I can't see your pics in an enlarged format for some unknown reason, but it looks like there might be yellowing of the outer part of the leaves. make sure that the ferts you use have everything plants need. there's about 16 different nutes altogether, but read the labels, do some research on what plants require, and only buy the products that give the biggest value for the money, like Dynagrow, which is good in both soil and hydro.