adam2... I equalized the pressure when I noticed the differential(there was a definite air rush into the buckets), will check them again in a day or so... the goods were vacuum packaged inside the buckets...I'm going to reduce the amount of iron powder to decrease the volume of O2 consumed for future attempts (due to the irregular shape of the vacuum packs its difficult to determine the exact internal volume, or I could use the PV =nRT gas law formula to determine the amount of iron needed).. for future reference I'll try a bag and 1/2 bag on an empty bucket to satisfy my curiosity