From the information given I don't see anything wrong, but there might be some critical detail missing.
Its hard to tell what the light level of a screened in porch might be. Filtered direct sun (similar to dappled shade) would be better than direct sun, but if the plants are in a screened porch back away from the screens and the porch is shaded by trees you could be in trouble (but I doubt it, assuming you have a bunch of flowering houseplants growing there too.). The shoplights many of us use to start seedlings are not very bright compared to shaded sunlight, but they are much brighter than normal room/reading light, and they are on for an extended period, which is why they are better than window light, which is only bright for a few hours until the sun passes away (we tend to have little windows up north).
Low light would cause elongated plants. Yours just look like runts, which is generelly a water stress/nutrient problem.