So in addition to adding a keg system to my routine, I'm going to switch to all grain. I keep going back and forth between 5 gal and 10 gal coolers, but I typically don't brew very high gravity beers, so I think 5 gal will be fine. Here's my question; Should I be fly sparging or batch sparging? If I'm batch sparging, do I even need two coolers or can I get away with just one? Any help is appreciated.