Best place for carbon
 

I want to run carbon in my sump.

I put a cupful of carbon in a bag made of my wife's old panty hose and stuck it in between the sump baffles, it floated to the top.

Then I floated it in the sump, it seems that water would flow around the bag full of carbon rather than through it.

I'm considering just laying some loose carbon on top of an open tray on the floor of the sump.

Anyway I just want to maximize the contact time of carbon with water, what is the best way?

did you soak it before you put it in?

try tying a small chunk of base rock to it, or wrap an elastic around it..

The best way, I think, would be a reactor to run carbon. Have a piece of PVC pipe, put caps on both ends and pump water through it. I think that's the best way to run carbon.

Makes sense. If it could be fluidised (water flow from top to bottom to suspend the carbon) it might be more efficient.

I've wondered about that (fluidizing). Would the carbon particles grind down and release dust into the tank? Might still be better to just run it downflow.

Why not just put the carbon in a small HOB filter on the sump?

Good idea but my sump water level is well below the rim of the tank. Maybe a small internal power filter? I am going to try hooking a carbon container up to the output from my protein skimmer first.

Or a cannister filter if you have one (eg. Fluval or whatever). One trickiness is that it still needs to be run below the water level (since they tend be be non-self priming), but one way that I've seen people do to overcome that is just feed the cannister with a powerhead in the sump (instead of using the cannister's non-self-priming pump).