Since I have a 350 gallon tank I've been searching for bulk purigen, or cheaper alternatives to it. I know carbon is good as well but I like the fact that I can regenerate purigen. I found this knock off on amazon with 715ml for $20USD. It looks like purigen, feels like purigen, and smells like purigen. I'm wondering how different it is from it. Purigen is $57USD for 1L. 
The package says 715ml treats 100 gallons which is a lot worse than purigen treating 100 gallons with only 100ml. If the packaging on these is true then purigen is still a lot cheaper. But I'm skeptical of both their claims. Anyone have any idea what purigen could be? Perhaps something that can be bought in bulk and is just rebranded like seachem matrix?
Also has anyone compared purigen in a reactor versus just sitting in a sump/filter? I know BRS did this with carbon and found carbon to be a lot more efficient in a reactor.

The package says 715ml treats 100 gallons which is a lot worse than purigen treating 100 gallons with only 100ml. If the packaging on these is true then purigen is still a lot cheaper. But I'm skeptical of both their claims. Anyone have any idea what purigen could be? Perhaps something that can be bought in bulk and is just rebranded like seachem matrix?
Also has anyone compared purigen in a reactor versus just sitting in a sump/filter? I know BRS did this with carbon and found carbon to be a lot more efficient in a reactor.