Finished up our first all grain brew 2 weekends ago. A little daunting but we did our research and went with a 10 gallon cooler for the mash tun with a 18" stainless hose as the screen and used a 5 gallon cooler as the HLT. We mashed at 154 and lost less than 1 degree over 60 minutes then fly sparged at 168. Calculated efficiency was 86% a lot higher than we expected, but exciting non the less. We also milled our own grains, which had to help a bit. The 2 converted coolers and all associated hardware was just over 100 bucks and well worth it.