The big kids seem to consistently recommend watering coco plants when they have lost half their water weight. So if your containers could hold a gallon of water total in the medium, at around 8 pounds per gallon, you would want to water after your container had lost 1/2 gallon of nute solution at around 4 pounds. So like that. Letting your coco dry out too much will slow growth rates, and too dry coco will actually cause deficiencies to show.
Just check your containers by weight to see how often to water. And pay attention to the growth spurt that then slows down to teach you fine-tuning of irrigation timing.
I am glad they are looking better. It makes it easier to smile during the day when they are healthier and happier. And happy plants grow faster and produce more and better weight.