Jerry,
I think that's what happened to the lotus I got from Tinkster. It started out doing real well and now the leaves are all brown and really little. I've been tempted to try to drag the barrel to a shady area. I found a couple small lotus tubers in a pot that wasn't doing much (over taken by cannas, etc.,) and emptied it and repotted them, they look a lot better, they get more shade, but they still have not gotten any buds. Wish I too, knew what the problem was, only fertilized them each with osmocote when I transplanted them, thought that would last for at least three months or so.
Good luck whatever you decide to do.