Hey bosscat. Plants look amazing, I haven't seen them in a couple of weeks and boy they've grown
You've got to be pleased with them, I would be.
So, when the plants are in flower their demands go up, some plants can be greadier than others for phosphorous and potassium and when using LED calcium also. This can appear as a deficiency that can colour leaves as the plant extracts those stored elements from the leaves to compensate.
But can also be caused by what's called lock out. Sometimes something in the soil isn't right ,wrong ph for example stopping the plant finding the nutes available so it feeds from the leaves again. Also if over time there can be a salt build up in the soil that causes lockout with same result.
That's the bit that takes experience, knowing whether it's hungry or lockout.
Lockout
Some nutrient companies tell you to flush (rinse the soil) at some point in their nute schedule. Do you know if bio bizz suggest a flush.
Deficiency
Like I said, can be simply a case of adding a little supplement of more demand on a simple mineral.
To me it looks like a small k (potassium ) or mag deficiency. That's why in late flowering I add a little extra on top of the base nutrient. p (phosphorous) and k (potassium ) booster and a little cal/mag.
I use Buddha tree pk9/18 and terpinator which is high in k. Not too much cause they're strong.
Bio bizz will have their own versions.
But before you add anything, check their nute schedule to make sure if they advice a flush.
Excuse the long waffle.
I can see the flowers starting to form.
