the kids are sick!

I started growing plants in an aerogarden about 5 weeks ago, since then the plants have had their lower leaves start to form orange spots and slowly die off. I have 3 plants and i think it might be a bit over crowded in there. Now the fan leaves appear to be too heavy for the stem and are drooping and starting to get black spots.... I'm not sure whats going on or what i can do to rectify my problem. Any advice? I checked on the post with all the potos and descriptions of plant issues but had no luck even loading the images. Attached is are photos of the original orange spots and the new black ones.

If the top new growth is looking like a healthy green then you are fine...lower leaves will always start dying off first. As for when they start dying off depends on a lot, most importantly if the lower leaves are not getting sufficient/strong enough light, they will start to die off as well.

looks like calcium deficiency...