Originally Posted by bhamade
Ok, so basically I let the initial mash water actually do the conversion then the water from the sparge is to help wash away the converted sugar into the wort?
Yes, assuming you're using a single step mash. It's no different than a batch sparge, except with a batch sparge you "rinse" the grains by refilling the MLT and draining again, whereas with a fly sparge you hold the grains essentially in suspension and flow clean water through them to pick up any sugars left behind by the mash. Either way, the starch conversion takes place in the same way.