S&G units are for "polishing" the water - removing very fine particulates. While all filters have some bio action, that is not its primary function....
It's like a car manufacturer making a lot of noise about their high-mileage models, but not listing the mpg anywhere. I get it, omissions happen, but...
Finally caught one of the white ones. Indeed some of the kuro spots are fading but some remain quite dark and perhaps are darker. Have pretty decent...
