Hey there Kansas, I gotta admit I don’t know why you’re asking about this stuff seeing as how picture perfect everything is right now for you. If you’re worries about the burnt tips , you might as well dial back the NPK just a touch , but if you don’t the plant will muscle through it as it grows anyway. Same with the cal mag, yes you always need it , but you’re already adding it. So don’t stop. The fertigation frequency is less important following the wet dry cycle correctly . And you’re doing totally fine. Hope this helps ! 🚀