I have 3 6500k t8's ATM
It just looks bright because I took the pic during a wc and the tank wasn't completely full
Im currently dosing 6ml of excell daily
I have not had to fertilize this tank yet(except root tabs on start up). I actually still have to do large wc to keep my N and P down......it's like the tank is even planted. The plants aren't dying but they aren't growing either.
Based on your plants a RAY II might xause some serious algae but then again your tank is pretty deep. It might just be right.
Definitely want to start CO2 and proper ferts. If you keep your N and P down your plants won't grow because you keep removing them...