Purigen didn't regenerate well
I regenerated my purigen for the first time yesterday. It was in my tank about 3 weeks and turned a brownish tint. I soaked it in a 1:1 bleach water solution for 36 hours and it's still just as brown.
I left it in its bag when I soaked it but I'm now soaking again outside the bag.
Any ideas why it's not working well?