Lotus Seed Germination - How Long?

I bought lotus seeds on ebay and am trying to germinate one. I sanded
it down just enough to see cream (defnitely not too deep) and the first
several days in the water, it didn't seem ot be doing anything (water
remained clear) but then the seed got much bigger as it took on water
and I was changing the water twice daily due to cloudiness. However,
it's been basically at that state for the last two weeks. While last
week, in the water the dimpled end of the seed would always be on top,
it has begun turning now and an area 1/3 down the side of the seed now
seems to be always facing up. I keep the seed in a room about 75
degrees and always change it with warm water. At what point do I give
up on the seed?