I've researched more about this topic. Found some interesting information to share -

Should i use red and blue?
Red vs blue spectrum
Why use some 65k's when in flowering stage?

The spectrum mix for flowering is actually recommended for minimizing stretching, and more quality buds. So I've just switched 3 of the 65k's to 27k's. I wish I had done it at the start, they've stretched quite a bit now, oh well. :greenthumb: