RQS Royal Jack Automatic first grow

Day 43 (18/04/2024): Plants look fine. Day 44 (19/04/2024): Had to raise the light slightly so it would be 26 cm from the tip of the right plant, which has reached 63 cm by now (The height measurement from the other day proofed to be wrong). I am almost out of vertical space and hope that the flower stretch will finish soon. The left plant stopped showing more leaves yellowing, but started showing some sort of new deficiency or excess - burnt leaves tips on the top of the plant. The exhaust fan was set to turn on on 64% RH to keep the RH around 63%. Day 45 (20/04/2024): 420! The deficiency on the left plant is looking worse, with a lot of burnt tips on the top leaves. Watered the plants using leftover mixture (3.2 L of dechlorinated tap water and 1/2 tablets of Easy Bloom), giving 350 ml to the left plant and 1050 ml to the right plant. Day 46 (21/04/2024): The yet unidentified deficiency on the left plant is progressing upwards, with more and more leaves turning yellow. The right plant looks more healthy, still stretching a little bit. Day 47 (22/04/2024): Cut two of the smallest micro bud sites completely covered in the shadow without the possibility of normal development on the right plant. The right plant has reached 71 cm and I had to put the light in the highest possible position, meaning I have ran out of vertical space. The distance from the tip of the right plant to the lamp is now 20 cm. If it continues to stretch, I will have to remove the metal grill the right plant is currently standing at. The deficiency on the right plant was successfully identified as potassium deficiency, with the help of the community. Since I am giving RQS Easy Bloom, which is quite rich in potassium itself, but the left plant is drinking very little, I will try to increase the dosage during the next watering, which is tomorrow. The exhaust fan was set to turn on on 63% RH to keep the RH around 62%. Day 48 (23/04/2024): The right plant seemingly stopped stretching. Removed a couple of completely dead leaves from the bottom of the left plant, and one from the bottom of the right plant. Prepared the watering mixture, using 1.5 L of dechlorinated tap water and 1/2 tablet of RQS Easy Bloom. Watered the plants, giving 400 ml to the left plant and 1050 ml to the right plant. They didn't show any signs of overwatering afterwards. Day 49 (24/04/2024): It is yet unclear if the increased feeding has helped with the left plant deficiency. I will assess the plant tomorrow, and if the deficiency is progressing, I will perform flushing, since I have been going quite hard on nitrogen at the start of the grow and the pot has very poor drainage, so it might as well be the nutrient lockout caused by the salts buildup. Also later in the day, one of the large ill-looking leaves on the left plant snapped and fell off when I was trying to tuck it.