PS: Invest in a big box of smoke pellets like these:
They are great for working out what your airflow is doing.
Is that really wise? Is the smoke "clean" or does it leave residues? I would love to see some pictures of someone testing the airflow of a mining rig with smoke.
The smoke didn't leave any residue on my fan blades or the inside of my case so I assume it is safe, they are usually used for testing cooker vents and such things like that.
If/when I have to test it again I will record a video but it won't be for some time now as everything is setup and working perfectly.