Devil Driver x Toaster Struedel Coco

GH Nutes were mixed into 1lb/gal stock solutions with distilled water. Installing RO water system for next week. Some plants developed what looked like mg deficiency in the first set of true leaves. Delayed shipping on nutrients meant I only began fertigating on 3/30, working quickly up to the 9/13 gallon dosage. Calmag was added midweek. Plants look generally healthy with little to no leaf twisting on new growth. 4/2 roots are showing at bottom of solo cups, do not feel the soil is adequately colonized by roots therefore will delay up-pot a few more days. Temps 77-80 RH 75-80, tapering humidity slowly, no signs of bacteria or mold however so I am not rushing it. Light is running at 100% Suggestions for better free app for USB microscope? The flower shots are an Exotic Genetix Rainbow G freebie that was abused the whole run. Seems to be light yielding but producing nice bud nonetheless.