I grew sanchu in a miso pot and a 2-liter PET bottle. I wanted to observe how long the roots would grow.
The sanchu in the miso pot grew longer than the one in the PET bottle, but its stems were thinner.
I found one sanchu with yellowing leaves, probably due to the cold or a lack of nutrients. I replanted it in a hydroponic system. It was very small and fit inside a tomato can.
The roots were white, long, and strong. Now it is growing freely in the water.