Yellowing leaves on my baby girl?

Copied and pasted this from the Troubleshooting forums.. please somone take a look..

S=Answer if you grow traditional soil --compost?

E-indoor (started outdoor for 45 days, switched indoors for flowering)

E-soil

CSL-compost?

SCL-Superthrive,Fox farms Big Blooms, Open sesame

E-Water source - tap
E-Source water pH -N/a --no tester yet =(
E-Age of plant--57 days old
E-Type of fertilizer--- Fox farms

E-Lighting source and distance from plant--2 5000k and 2 2700k floure~,and 1 CFL Unknown lumins
E-Air temperature 80 in the day,60 at night
E-Air % Relative humidity --- N/A
E-Lighting schedule--12/12
E-Type of ventilation your room hasAir circulating air inside.. small holes to pull the air in and out

I answered to the best of my knowlegde.. this is my first grown with very limted resources... The leaves at the bottoms are turning yellow and falling off, I did flush the soil last week before the yellowing started, could this be the cause? Also I've only added my nutes into it one time.. And I was getting a bit of a bug infestation and I added chopped up peices of garlic to the top of the soil.... Please if anyone has anything that could help save my baby ='( let me know