To get rid of the "Brown Scum" in your HHO generator, only use non magnetic, non-rusting stainless steel. Also, only use distilled and/or rain water and unsweetened Cool-aid in your cell. Always wash your plates in distilled white vinegar before assembly. Run your cell for 1 hour, then let the oxidation settle. Pour off the good water and clean the cell with distilled water and distilled white vinegar. Now you can put the clean water back into the cell. Your ready to go, no more brown scum!