OK, I'm def in the Purigen camp. tank been a lil cloudy lately so I got the 250 and a bag. within 2hrs you could see it clearing. by the next morning, lights came one, bling bling like the gum commercial.
dont know if the inner surface is as brown but the outer is, guess I'll let it go for the month before recharging.
oh yeah, its in my AC110...