Yellow Leafs

Could be zinc deficiency. Whatever deficiency it is, it's very probably caused by high pH. Organic fertilizes are not supposed to create salt build up Anyway, 4 bio tabs sounds as right amount for your pot (20 liters?) Question is does your pot has draining holes, what is watering pH and what is run off pH

Cannabis potassium deficiency symptoms typically appear in the flowering stage. They can include: Yellow or brown leaves, usually—but not always—starting with the tips of the oldest leaves, before extending further in the leaves and upwards to newer growth.

The leaves do look like potassium but I would expect to see this on the lower leaves as its mobile. What is your mediums composure? and does it only have biotabs or is their other stuff in the mix? Calcium normally presents its self as spotting on the leaves vs yellowing on the edges. It could be slight burning from to much feed as the rest of the plant is looking quite healthy. Warm temps helps breakdown amendments faster and the synthesized slow release fertilizers also release faster in warmer temps. Good Luck!

Potassium is mobile can't be caused by K, symptoms would show on old growth first.

New growth so it's immobile nutrient. Next is to look at where the yellowing starts from within the leaf, this creates it looks like it starts on the edges and works its way in. Sulphur works from Inside out. Nitrogen is mobile not that. Magnesium has yellowing with interveinal chlorosis. Also mobile. I'd have to say calcium, early stage, only one that works outside in without chlorosis. And it's immobile.

looks like lack of potassium, she entered flowering, needs more PK than N.