If H2SO4 is always added to the H202, I guess spiking isn't an option. I typically add H202 to the bath(spike) till bubbling "nicely". Change bath at least once a week. Roger Shile -----Original Message----- Hi, It is definitely add the acid to H2O2. In Portuguese there is an easy way to remember: H2O2 and water are feminine nouns in Portuguese, so we always have to remember: ladies first :) Virginia Soares