Feeding should be done by ppm. Week 1 is seedling. No nutes until your first 3 finger leaf set. Then feed 400 -500ppm @6.3 pH 1 feed one water one feed one water. Mix the nutes you plan to use per the manufactures recommendation (5ml per gal etc etc)
in a 1 gallon storage container, then add 1/10th to a new gallon and the rest with 6.3 pH clean water. Measure your ppm. Under 500? Add a little more to get up to 500. Over 500 ppm? Drain off and replace with water until you're close. Always pH 6.3 and make sure it's stable about soil temp before feeding.
The Sapphire OG was a hard start for me too, but at week 6 after it rooted I have 12 colas ready to flip this weekend and healthy
like 1