Old and New domain compete for ranking, what to do?

Hope someone can help.

I made a 301 redirect from my old to my new domain, the new domain get pretty good indexed already. however, in SERPBOOK I can see that the new domain is on spot 5 and the old domain on spot 12 - it is one and the same URL is there anything I should / can do or will Google just drop the old URL anytime in the future?

Another question, can the above take linkjuice from the new domain doing so or it doesn't matter?