Warning- bad carbon will kill

[Seamazter]

I had bought some quitencence carbon from wai;s a few years back.
It was the wai;s branded brand.
But i had huge diatom problems, 2 days after i removed the carbon it cleared up.
I have been told a few times, that the carbon absorbed all that it could and was starting to leech it back into the tank.
If u remove your carbon for 2 days then id say its your carbon too.