Just can't seem to get it right

[bigblue]

This year in my first attempt at tomatoes and peppers from seed. I successfully germinated some seed (both hots and bells) a while back and the seedlings look healthy but are so small. I have not seen anything grow this slowly. I have to be missing something. These plants are 5 weeks and are between 3” and 4” tall. They are under lights, but every other day see window sunlight for a few hours. The lights are florescent tube and about 5” above the plants for 16 or so hours each day. They are planted in Miracle Grow Organic Choice Potting Mix and get Urban Farms Vegetable Fertilizer at ½ strength once a week. Any suggestions?