That makes sense. Guess I need to look for a second co2 tank. Thanks for the info!
Or just get a distributor box. Or a dual regulator if you want different pressures on each keg.
I just have a single tank/regulator myself. If I'm carbonating one beer while I have another on tap, then I leave my gas on the beer that's carbonating, then just "top off" the keg I'm serving from as I need it.
If you're carbing multiple kegs at once, then you can just hit each keg with gas a couple of times a day at a higher pressure than you're carbing to. I start with 30 PSI the first day or two, 20 PSI the next few days after that, then 15 PSI. It's not ideal, but it lets you make do with what you have.