I assumed it would be enough if the container was just 1/4-1/3 full, when I have space I also do that, I'll try a full on water container next time. Btw that's also a great way if you have chopped carrot sticks, they stay fresh for the next day(s). I think this works with all root vegetables since, well, it's roots that are meant to take in water and transport it

I don't know whether this works in a horizontal position actually, I always assumed smth smth gravity, but on the other hand, when you fully immerse them then gravity can probably go out the window.