I used to dual boot manjaro and fedora but i deleted my fedora partition because i needed the space and manjaro was just better. i ran into the issue of merging unallocated space and my root partition, is there a decent way to do so?
This can be done with a Manjaro live ISO or GParted Live.
You boot into the live environment, and then use KDE Partition Manager or GParted to grow your existing partition into the available space. (The filesystem cannot be mounted during this operation.)
Just be careful, and make sure you hve backups of your important data.