Changing Tank Over

[Xebadir]

This is probably not strictly a beginner question but: my tank has been running as is for about 6 months now, and ive decided to change community to cichlids. the tank is fully stable, but for changing, id ideally like to remove the current stock, and stabilise the new conditions, then add the cichlids 2 days later.

Will this cause a problem with the nitrogen cycle?