When to move rockwool seedlings to dutch buckets

[gdgdad]

Stan, thanks for the quick response. I’ve provided a (hopefully) better pic and circled the “discolored” leaves that shows their position. On your comments / questions:
-The plants aren’t moved in and out, and actually have never been moved since being put in the Dutch buckets, BUT…. They’re only inches from the garage door (to get the most full sun) that I open in the morning, close in the evening.
-Watering: still set at 15min off/ 3 min on 24/7 (reduced from 5 min on). I use an “open” (i.e. nothing on the end of the hose) dual ¼” drip line per bucket. See the pic with the “hoop”, I cut the hoop at center and left ends open, pushed down ~ 2” into perlite. Per my measurement on the return line, I believe each bucket gets about 10 gph. (if running continuously). Increase time on?
-My PH tester is a battery operated ATC – iMeshbean PH tester (https://www.amazon.com/iMeshbean-Dig.../dp/B00LE3MZ7S). I also bought Atlas Scientific calibration liquids and check the tester ~ once a month and it’s dead on.
-Fertilizer: still using Miracle Grow® for tomatoes (@1/4 strength) – open to your recommendations – type and strength….
-On the air stone(s), I’ll turn them on manually in the morning for ~ 2hrs. until I grab another timer from good ‘ol Harbor Freight.