I have beenusing it instead of carbon for over 2 yrs now and have no complaints, it seems to be doing its job. It is just a resin like what is used in bags of chemi-pure along with its carbon. It does not remove trace elements like carbon does. I would buy the prepackaged little bag of it instead of the bottles because there are some really small granules and you have to get a really small mesh bag to hold the smaller ones, the prebagged is good for a 100gals i think. It turns a lite tan when used up and i don't reconstitute it i just toss and use a new one.