you have a great start...You got some good advice and some a little on the edge...

your ph at 6. is fine, but you might want to lower it to 5.8 once you go to flower.

5.2 is too low...I only use a solution of 5.2 when soaking rockwool!

Advanced Nutrients tell you to lower ph each week during flower to target certain nutrients. the optimum uptake of each element is at different .points-.'s of the ph scale.

always use all the airstones you can in all your rez'z
Oxygen is paramount to successful hydro/growing and the more you oxygenate the fluids, the faster your plants will grow...This is a fact!

From the looks of your plant, you can go with an HID right now...No need to wait...The more light you put to them, the bigger/faster they grow. fluoro's are great, but if you have option of "BIGLIGHTS"...then use them. goodluck, lw

P.S. I think you have got a great start and I look forward to helping you out, whenever possible. I gotta go!!!