Go to cocoforcannabis.com it will teach the basics of coco but you should always fertigate (feed+water) coco right from germination.. I buffer my coco for 24 hr then soak it in week 1-2 solution 500ppm then flush with 300ppm before planting.. Once they sprout i start at 250-300 ppm once the first true leaves are about 1" long I slowly increase feed to full strength(500-650ppm) over the coarse of 1-2 weeks