So I was doing a test since our water lettuce roots couldn't keep up with the growth and rate we were shipping them out. Took a few real bad ones out and tossed them in a bucket with 3 pinches of Muriate of Potash. Pretty cool to see what a little bit of potash can do to the growth. And this was with just tap water not pond water. So no nitrates, just the potash. So this is about 1 week.
Plant 1
After
Plant 2
After
Plant 3
After
Plant 4
After
Top Views of 2. Lighter green since its in the sun more
Plant 1

After

Plant 2

After

Plant 3

After

Plant 4

After

Top Views of 2. Lighter green since its in the sun more

