I really need help. I am a new grower and have tried to research but getting more confused.

So info are as follows:

Medium: Coco 60% and perlite 40%

Age: 33 Days old from seed

Light: Luma 1200 Cob LED Grow Light (18/6 cycle)

PH Level: 5.6-5.9

Feed two days ago with following mix in a gallon :

Canna Coco A&B - 2.9mls each

Cannazym : 3.4mls

CMX Flairform (Calcium, Magnesium, Maganese, iron, zinc, copper, molybdenum and ) : 3.5mls

Regen A Root CX (Root regenerator) -3mls

Humudity: fluctuates between 40%-63% majority of time, however, lowest has been 38% and highest 99% (very short period 10mins)

Temperture: majority of time 21% - 26.5%

TALL/LST'D PLANTS- had noticed bottom leaves were yellowing and brown spots so took off plant. However, it is continuing and bottom part of plants are more yellow/light green. Newer leaves burnt tip/spots/tacoing up.

It started with tip burn about a week ago so flushed with PH watered @ 5.6 and then gave above mix three days after. I am unsure what strain, however, I have another strain (SHORTER PLANTS) which has had the same flush-feed as taller plants. These ones are no where like taller plants other than bottom leaves are yellowing.