How to plant Bog Bean

I know this is going to sound a bit dull but can someone tell me how to plant Bog Bean please? The plant I have has long feathery strands that come off the main stem and go about half way up. Are these roots or leaves, I'm not sure, think they are roots? Should they all be covered with soil? I will need a very large pot if so. There was no advice about these on the planting instructions.

 

“Best planted in a shallow square 2 litre aquatic basket: lay across top of empty basket with roots draping into basket and growing tip pointing up, fill around with soil and firm down. Add gravel to finish and if necessary weight the stem sitting on the surface of the soil with a small stone to prevent floating away.

Form: Bare root.”

 

. Instructions didn't say to do this