The spots on the leaf and slow growth is because you are experiencing a calcium deficiency. At this point you don't need to add this and should just let it ride but you should look at adding a calmag to your nutrient army.
The pictures of the buds are a little blurry for trichomes so I'm going by the bud as a whole, hairs turned in and 80% red. With hydro you only need to run plain water for 72hrs before you cut her down, I'd check back with some pictures in 4 to 5 days for a go ahead to flush.
You say you have been watching and adjusting your PH Daily, Does it keep dropping and you are bring it back up?