I have to agree with
@DunkingDave on the watering schedule. With Coco the more frequent you water the more oxygen your roots get and the quicker your plants will grow.
It's also possible to have your led to low and slow down your plants growth without causing any bleaching or even any significant calcium magnesium issues.
Sometimes Growers new to Coco will allow that Coco to dry out a bit before they water. This will cause their roots to stunt and die back and the plant will stay perpetually small. As soon as your plant is large enough to tolerate flooding your entire pot you should always flood your entire pot and get some runoff.
I listed those three things because they will give you a normal looking plant but your plant will just stay small.