I personally think skimming is skimming. I have a new Aquamaxx ConeS CO-3, and an old AquaC EV180, and to be honest, the skimmate smells the same, looks the same... I'm doing side by side comparisons now, but am not so impressed with the new to say, old is old. Kind of cryptic I know, but still am testing and haven't drawn up all conclusions yet. Good luck.