cycling and nitrate level question

[topcat31]

Hi I have a 46g tank that I have been cycling for nearly 6 weeks. I started with a tunze comline 3162 filter, a tunze 9004 protein skimmer and 2 6015 power heads. It has a 2inch substrate bed and initially had 20 pounds of cured live rock and 27 pounds of uncured live rock. Ammonia and Nitrites when up and back down as expected and have been at zero for nearly two weeks, however my nitrates keep rising.
Is my cycling not yet complete? Should I just let it cycle longer (I'm in no rush for fish) or should I do a partial water change or add a nitrates binding additive?
Thanks for the help
Joanne

[shifty51008]

nitrates will go up after the cycle is complete, do a water change to lower them back down

[topcat31]

Thanks shifty51008. I will do a water change today and retest nitrates (currently 40ppm)