Brown spots/yellowing of leaves... help?

Alright so, this is my first grow, and my two plants are about 3 weeks old now. One of them looks perfectly healthy, but the other one hasn't been looking so hot since I transferred it last week; it suffered some root damage. Its leaves were very yellow and droopy for a while, which seemed to go away once I gave them a little more light. However, now the leaves are starting to droop and become discolored again, and there are a few brown spots on the lower set of leaves. I have not given my plants any fertilizer because I didn't want to give it to them too early. Any ideas on how I can save my plant?

Hey i wish i could help you but im new im kinda having the same problem with 2 small white spots on my 5 day old plants, another plant seems to be bending just a little bit not to worried, maybe someone with info will post here to help you, post some pics of your plants im posting some as well on my forum id like to compare our plants as they grow tho you'res are a little older then mine, my oldest are 7 days