Carbon in filter sock? or in a chamber?

[Zoaelite]

A dosing station uses peristaltic dosing pumps and supply reservoirs of chemicals to maintain your levels. For example my bubble magus dosing station doses 2.08ml of both CA & ALK solution 12 times daily to add 25 ml of both solutions. The third one doses 2ml of Mg twice for a total of 4ml, so far it has been working flawlessly.