After the coco is properly rinsed and charged, I do a final rinse with 0.4-0.5 EC nutrients. I take germinated seeds and put them in the coco/perlite in solo cups.
Once the seed pops up from the coco, after 24 hours I'm feeding nutrients at 0.4-0.5 EC. Some people wait for 3-7 days before feeding nutrients because the cotyledons will provide food to the seedling, but hitting it the next day with nutrients makes the growth take off during the first week, which makes it possible the next week to...
On day 8 or 9, I increase the EC to 1.0-1.1 EC and top out at around 1.2 EC in veg, and top out around 1.3 EC in flower. Always feeding multiple times per day - seedling to harvest. If one feels sketchy about feeding at least once a day during seedling, increasing perlite to a 50/50 ratio will ensure no problems.