I put a few of these in my mum's small pond and they were doing ok although now the edges of the leaves have going brown and look like they are disintegrating or have been nibbled (??) by something. They haven't flowered since I put them in a year ago.
Hi It sounds like water lily beetle especialy with the edges being nibled mmmm dont know how to get rid though Spruce
Thanks for the reply. I'm only guessing that they may have been nibbled as thats what it looks like. They may just be rotting away for some reason.