By default, I have a lot of screen tearing when I use Firefox in i3. I downloaded picom and tweaked the settings a bit, and I've found that if I run it in a terminal in i3 (pycom --config ~/.concif/picom/picom.conf) the screen tearing goes away. I'd prefer to have it automatically run when I start i3. I'm using xorg, if it matters. How can I do that? I've tried adding exec picom --config ~/.config/picom/picom.conf & to the end of my ~/.config/i3/config file, but that causes i3 to have a grey background at start and have a strange loading cursor, so I don't think that is correct.

So, what's the proper way to run that picom command when I start i3?