With coco, you should use nutes that are made for coco, or at least give extra calcium in the form of a CalMag Plus supplement. That's a coco 'thing' - Ca deficiencies.
Also, many people find that cutting the coco with perlite significantly helps drainage.
Feeding and watering coco is most easily done with drip-to-waste, but you can hand water IF you can guarantee that the medium will never fully dessicate. Once it is allowed to do that, it is difficult to re-wet, and may start causing problems.