Stained leaves

Like others said, drip line and Biobizz is not a great combo. I think I told you a couple of times now, that with Biobizz, what you feed today won't show an effect until 1-2 weeks later :) So, that you're feeding 2ml NOW, doesn't say why it looks the way it does now, what you did 1-2 weeks ago is why it looks the way it does. You're still underwatering, same nutrients around this time and proper amount of water would change things drastically, and bumb Bloom and TopMax to 3-4 ml/L soon.

Could just be genetics...looks great

Since you’re using BioBizz organic nutrients with drip irrigation, I’d check for partially clogged drippers. Organic nutrient residues can build up in the system and cause uneven watering. Check that every dripper delivers the same amount of water, and clean the system according to the manufacturer’s instructions if needed. This could explain uneven growth or yellowing, even if your feeding schedule is correct.

potassium & nitrogen perhaps ?

Hi did you fill the pots to the top?

Rule #1 of fight club..... Dont use organics when you use drip lines. Almost a certainty to rapidly form biofilms and clog lines. Constantly flipping between master regulators switches ToR and sNrK1 every day as your plant cannot make it through a day without crashing the krebs cycle everyday from a lack of water and oxygen. Blah blah blah add more salts or bottled remedies. Goodluck

If only the lower leaves are yellowing and it's slow, that's fairly normal in early flower, since the plant moves nitrogen up to the buds. If the yellowing keeps climbing, it's nitrogen, so check that your water pH is 6.0-6.5 and raise the Biogrow a little instead of adding more Topmax. The buds and tips also look very pale, so try lifting the light 5 cm or dimming it to 60%. If you alternate feed and plain water, let the pot dry a bit between waterings.

bump the N a little bit while maintaining other levels of nutrients as best you can... if the drip system is part of the problem, you need to redesign the drip system.... does it full saturate? is it leaving dry pockets? is there too much difference in watering needs from pot-to-pot causing some to have excessive runoff? (more relevant for issues in soil, and generally a good thing for soilless...but, potentially dilutes soil faster than the other pots)

1. Using organic fertilizers in a drip irrigation system is not ideal. Organic particles can clog your lines and drippers. On top of that, the nutrient solution in your reservoir can go bad quite quickly. 2. It looks like a classic case of nitrogen deficiency. Nitrogen is a mobile nutrient. If the plant doesn’t receive enough nitrogen from an external source, it starts pulling nitrogen from its lower, older leaves and transports it to wherever it’s needed most. This means there isn’t enough nitrogen in your nutrient solution. I personally use mineral nutrients only. But since you’re in the flowering stage, I don’t understand why you’re using Bio-Grow and Bio-Bloom. I’ve only used BioBizz once outdoors, following their feeding schedule, and everything went fine. My recommendation: Finish this grow by watering manually. Clean your drip irrigation system thoroughly, and if you plan to use drippers in your next grow, consider switching to mineral nutrients. If you stick with BioBizz, follow their feeding schedule, especially since you’re already in the flowering stage.