It is possible. You have to make 2 holes for the fluid dynaimc to work. One hole just above the bottom connector (1/4") and another just below the silicone cap, so that the liquid can flow into the sealed compartment of the CEs. I did it with a CE2, once, but don't prefer the CE-type cartos. The Vivi Nova
tank is comparable function to a CE-type carto, but you have the benefit of being able to rebuild the heads and seeing your nicquid level (~3ml). The Vivi Nova may be great out of the box or you can modify it for better production. The jury's out on the "Greatness".