So I trimmed on Saturday the 8th, and it looked like this:
Ten days later:
Only dosing to date is .2 (not a typo, point 2) ppm of K2SO4. The low grow hygro has been growing, but growing with micro leaves. Friends suggested trying a little potassium in the water column, as some plants, like this one apparently, start to grow little tiny leaves if getting the nutrients all from the substrate. Leaves have begun to fill out more, not sure if it is easily visible in the photos, but that little bit of potassium seems to be helping it.