If you want them to grow better you should water more frequently.
Coco/Perlite cannot be easily over-watered. Conversely, as it dries, EC climbs precipitously. for both of those reasons, you should keep it wet!
To get the benefits of Coco you should water at least everyday, and 2 or 3 times a day in flower.
I will recommend my guide again, because I think you would benefit. Link is in signature above