I usually run into cal/mag issues but later in the grow. They never seem to impact significantly but make things look ugly. I have seen similar problems and once I raised the lights , things got better. Now I start at 30 and sometimes never move. I only start in rockwool then drop into coco at about 15-20 days. Once in coco, I water to runoff( along the outside edge of the pot). It may be tied to strain, some strains I haven't feed nutes until wk 3. On others that I feed once it pops, I never go over 300ppm for the first several weeks. good luck !
