OK, a bit of a problem. I processed (1) a roll of 135x24 Fujicolor 400, (2) a 120 roll of Reala, (3) a roll of 120 Ektar, (4) two rolls of 135x36 Portra 400 simultaneously, and (5) a roll of 120 Superia 400. All came out well except for the two rolls of Portra (4). They have a brown color to the film mask. Is it bad to process two rolls at once? I used 500 ml in a Patterson System IV tank.