I think you have it backwards mate. If your box is five feet tall, that fluorescent light at that the top is virtually useless. Refer to the inverse square law, lumens and all that, lux, foot candles. I like my 400 in a cool tube 12'' from the top of my plants. I run my garden at 24/0 with a 400 in a 3 x 3. Use the 400 on the top, fluorescent as side lighting.
Water when pot is light. Keep surface of soil moist for seedlings with a sprayer. Not too much or you can have damping off and such. All else fails try youtube. I watch at least a half hour of grow vids a day while I pack up bowls and such.
Not hating, those pots are small and dreadful. You'll need at least a 1 gallon and most people say that is too small even.