I apologize, I thought this was the same question on the actual hub I wrote and answered something similar there. Noting that your question is 6 months old, I can only assume that the seed(s) was transplanted and thrived or failed to sprout.
If after 6 weeks, your seeds have not formed healthy roots or sprouted, they most likely will not continue to develope. I'm sorry. I would recommend at 6 weeks, transferring them from the water to a pot and hope for the best. Sometimes they will take off, and other times slowly wane down.
Incidentally, the two trees in the pictures on my hub were both rooted in planting soil as described in the "soil" method. You've given me reason now to grow one using the "water" method and write a hub about it so that people will have them to compare to. Thanks for your question! ~PM