help!!!! there turning yellow

[bongzilla420]

i am useing florescents and potting soil and i am watering with bottled spring water and the leafs on the bottom are starting to turn yellow what am i doing wrong??

 

[Insane]

What kind of ferts (if any) are you using? How often are you watering?

 

[bongzilla420]

i got miricle grow slow release all purpose and im watering every 2 days or wen ever its dry wen i stick my finger in it