I have many seedlings (dahlias, strawflowers, impatiens, and some herbs) that have been getting 16 hours of warm/cool flourescent lighting since they've germinated (about three weeks ago). They were transplanted to 20 oz plastic cups w/drain holes (from starting trays). Iy seems that their leaves are not a very dark green and very dull looking. The leaves are NOT yellow or wilted looking and the plants are very erect but they don't seem to me to look as healthy as they should. I'm wondering if they need a fertilizer boost or if it's from the heavy use of flourescents. (I used Schultz brand soils for seed-starting and transplanting, so I don't think it has to do with the quality of the soil. I'd like to fix the problem (if there is one). Thanks in advance for any advice you can give.
Have you fertilized them at all? I generally start to fertilize once they get their first set of true leaves so if you haven't fertilized them yet that could be the problem. The other thing could be that they're too far away from the lights although that would often cause them to be leggy too and you don't mention whether that's the case or not.