A coco hempy.
Just be sure to buy quality pre rinsed,pre hydrated,pre buffered,pre charged with Ca/Mg coco coir like Canna Coco and use coco specific nutes like Canna's Coco A and B and pk 13/14
Compressed/bricked coco varies so mutch from batch to batch and tends to be really salty and needs to be hydrated and rinsed with water pH'd between 5.5 and 5.8 and also needs to be buffered/charged with Ca/Mg.