How do you grow pond plants?

Question:can lillies simpl grow floating in the water or must they be potted? if they must be potted how is the water kept clear?

Answers:
generally, they are potted. There is special "pond soil" you can buy for it (theoretically to keep the water clearer than "regular" soil), and generally, you fill the top inch with silicate rock-stuff to keep the soil in place.

However, they are hardy and determined lil buggers, and I've had them grow unpotted in my pond - with the root-mass just floating around down there. I could drag the mass around.
either way, potted or no, special soil or no, the water clears once they "settle".

Also - even if they're potted, I recommend pulling it out each fall and hacking the roots back - because they'll grow out of the pot and try and eat your pond - potted or not!