Is it worth running carbon?

[ReefSaver]

I took my hang-on filter off my tiny 2.5 gallon planted pico shrimp tank and I was wondering if there is any point in adding carbon to it. I had an idea of just drilling a little tube in my oversize Log aquascape and filling it with carbon but I'm unsure if there is any point in using my carbon on the tank. Would it be inefficient because the tank is stillwater with no water movement or will it still help clear up the water and draw in elements?

 

[MacZ]

It's useless, honestly. It indiscriminately filters good and bad things.
Activated carbon can also only filter out a certain amount of things, at some point it's just saturated and sits there. Then it slowly breaks down and releases everything again.

A working biofiltration (aka the cycle) is much more important for your tank.