[quote=@DracoLunaris]
<Snipped quote by Lugubrious>

oh shoot, was I supposed to be handling their duration? I guess I'll be paying for that by not having them around for most of this boss battle then. or was that a warning that you'd be poofing them?  
[/quote]

There's no numbers to crunch, you should just be having them out for shorter bursts at a time. Do it more than way and you can still use them in the near future.