I used this as a reference: http://www.victoria-adventure.org/lotus/growing_from_seed.html
I have failed to raise one successfully to flower in my last 3 attempts. I think my problems are three things.
- failing to get into a pot soon enough
- failing to provide enough sun
- trying to raise in too great of density
They like it warm, and will not grow quickly unless they have a pretty warm environment, but too much direct sun can burn them.
Also, they don't tolerate changes in water depth well, you can put them in shallower water, but going deeper can only be done easily over winter.
Mine in the past tend to just die over winter, they fail to get enough energy to survive dormancy.
They're also very edible, so must be protected from ducks, etc.