Just did a water change in my 30. I had some growing in a pot, about 3 ft long. I took a hose and washed the dirt off the roots, wrapped with wire to a lead weight, some leaves are submerged but most are outside the tank, they only opening is the cutout for the HOB filter, that i ran them thru.Their best left floating the leaves need to be out of the water. Or at least this is how I see them in my local pet store.