SteveinSpokane, if you are consuming all your lump in 45 minutes at 650 degrees then you are not putting in enough lump to began with. Don't believe that 2 or 3 handful crap. Fill up to a least the bottom of the firering and then some more. No harm no waste because you'll snuff the fire and reuse what's left. OTOH 650 for pizza is kinda hot - are you sure you want that hot? I have found 500 works fine for me. Good luck.