#1....your plants wont make it to flower like this with your lighting situation.
#2....you're gonna kill tehm with superthrive....you're supposed to use one drop per gallon...I can see going over that a bit but you're talking 1/4 teaspoon I would re-read the directions

While your attempts are ambitious and admirable, your lights do not provide the spectrum the plants need...nor do they posses the lumens you need now and will later.

But, I cannot fault you for trying

Keep up the effort.