activated carbon

[Woodstock]

Can I just place a bag of carbon in the bottom of my sump or does the water have to be forced through for it to be effective?

 

[Lpabsolute]

Just place it in your sump and make sure it's completely under water.

 

[SumoBlenny]

You can put it in a high flow area in your sump. It doesn't need water to be forced through it to be effective. In fact pumping water through it can clog the micropores reducing its effectiveness prematurely. Not a big deal either way it will work where ever you put it.