i actually axed it from my filters last year when I read that there is inconsistent information out there on the product itself saying it might be viable for a day or a week so i removed it and have not noticed a difference however since removal suspecting it was true it was only viable for a day or two. I wanted more depth in providing cleaner quality water in between to my water change routine so added more sponge and biomedia instead of the carbon. I used carbon all of the time when I had my old fish room. Swore by it. Now I wonder if it was just because I did more water changes. That was at least a decade ago when I was last in the hobby until 2019 when I slowly got back into it not surprised if the same activated carbon i was using would have had changed in quality vs a decade ago too.