Does used carbon have to be promptly removed?

[Dag]

Somebody said that carbon shouldn't be left after it's been exhausted because it will begin releasing organics back into the water and/or nitrifying.

Do you suppose that's true, or any other adverse effects that result from leaving your carbon too long after it's been exhausted?

[Randy Holmes-Farley]

I'd remove it after a while (1-2 months, typically). It may release organics that are bound to it, but that is only likely if it binds other organics in their place (or they are consumed by bacteria on the carbon).