Thanks for the advice. So it does take a lot more water to fly sparge than to batch sparge, correct?
I.E:
batch sparge: 4 gal in, drain, add 4 more gallons, drain = 7 gallons in the kettle
Fly sparge: 4 gal in, if I want 7 gallons in the kettle I need 7 gallons in the HLT for sparging...