Please help diagnose what’s up with my plant

Current set up
8 inch outtake fan
6 inch inline fan
Coco perlight 70/30
Flora trio
Week 7
Under 600w hps currently down to 400w due to heat
Ph to usually 6.5
Current run off is around 6.2 / 5.7 different plant

Some leaves are very dark others quite light and turning yellow

They look Ok. That yellowing looks pretty normal for an inside plant. Likely due to low light to the lowers.

I don't see anything to worry about..