I took my syringe tank and drilled a hole up top on the side of the tank, a hole just big enough to squeeze a carto plug in, dam thing works perfectly and now its a simple fill using a syringe, I'm using my original Maptank delrin caps which fit snug as a bug on the syringe tank so no need to even pull them off any longer unless I'm changing the carto out. wrap a clear piece of scotch tape around the top cap and bottom cap for even better air suction and it not only pulls a bit more liquid into the carto now but also holds the plug in place. It's not the prettiest tank but functionality it works like a dream with a DC Carto and is dam easy to fill now with the hole and plug.