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,

Tap or pond water? ~ jan

Tap water (I think!!!) - I have done this 2 or 3 times and am sure I used
tap water at least once, if not every time - have not had a problem
sprouting Lotus seeds and getting viable plants - using tubers is another
whole different story !!!!!!!!
Gale :~)