I fly sparge; and most recipes I do call for a sparge water temp of 168 F. I keep the HLT tun at 170-174, to allow for a bit of temp loss. Sometimes I do a no mash-out ( Irish red , baltic porter, weitzenbock) and the mash is at 152. Makes for a smooth beer, no off flavours, but yield sometimes suffer a few points. See mash profile med body single infusion no mash out in beersmith