SweetLighter

I'm no expert, just a believer in "general wisdom," so I'm having a hard time understanding this..

Activated carbon is supposed to do its thing because each little piece of carbon has millions of microscopic holes in it. So these millions of holes work like a sponge and absorb stuff from the water, like DOC, but also trace elements and minerals, so it's not a good choice for a planted tank..

Purigen also is said to work like carbon, each little synthetic bead has millions of microscopic holes.

So if it works the same way as carbon (like a sponge with micro holes), how does it only absorb "bad" stuff but leave the "good" stuff (like trace elements, vitamins, etc) alone?

I believe the quote from Seachem is "Purigen's impact on trace elements is minimal."