I took my new 2016 Novara - Safari out for it's first ride today, and upon returning I heard an intermittent spoke hitting sound. I suspected that one or more spokes were contacting the front disc brake caliper, and that's exactly what it is. I flicked each spoke and found some of considerably lower tone/tension than others. The offending spoke being one of them.

The rims on my bike are "Alex ATD 470".

Now here's my question, and I am new to all of this. My assumption is that all I need to do at this point is get a spoke adjustment tool, and tighten the looser spokes up to the same tone of the tighter ones, and that will likely take care of the issue. Is that the case? Also, is there a specific level of tension or tone I should be setting as a target for my specific rim? I understand that I would have to purchase a fairly expensive spoke-tension measuring tool to find out what the current tensions are, and then set them all to whatever the specified tension may be. I'd much prefer to skip the expensive tool purchase if possible at this point, and just do what I said previously about bringing the lower toned spokes up to match the higher ones.