I was thinking of getting a 5 gallon cooler to serve as a HLT and complete my 3 tier system. I was gonna just heat my sparge water and dump it in the cooler then attach a valve (similar to my mash tun) and attach some silicone tubing to that which attaches to a fly sparge over my mash tun. So, what is the difference between coolers, kegs, and pots for HLT? What have your experiences been? And if I get a cooler do you think 5 gallons is big enough (I'm only doin 5 gallon batches now)? Thanks