If you can get it, Canna Bio Terra Plus is about the best I've seen, but it's expensive and you need a Canna dealer to get it. It's basically pre-amended coco, the best grower I know uses it and he usually gets over a gram per watt with buckets of it in an Ebb& Grow. He only adds a little Bokashi compost to it and then feeds with Agricultural Organics nutes. Last run was 11# out of 9X600W, pretty damn good.