Yelow brown

Whats your feeding PH and EC and what is your runoff PH and EC ? I would guess you dont feed them enough from the first look ✌️🏻

Kinda looks like a phosphorous issue to me.

@GrowingGrannie no, I actually give 100% because I finish on half a liter. 2ml on 50cl. my ph is always around 6.0-6.5. I'm not stuck with a lock or something ... it's now my 3rd grow and it always goes wrong at the same time approx. really frustrating 😅

This is your LSD grow, yes? You're not feeding her enough and she basically needs more of everything you're giving her. The Alga Bloom, for example.... you're only providing her 2ml/L when the max is 4ml/L so this should be increased to 3ml/L ... same with your PK 13-14 - what you're seeing here is a phosphorus deficiency and so the PK 13-14 needs to be doubled. It's important, when mixing your nutes, that you add the PK to your water first... then add the Alga Bloom. You should also raise your pH to 6.2 minimum as this is the ideal pH for phosphorus absorbtion in soil.... Good luck!

#NeedsMoreCalmag! Personally, looks like nitrogen deficiency, since it is starting at the bottom working it's way up.