Well Eclipse you've really made a crazy mod. After reading a few of these posts in this thread I went out today and bought some carbon foam that looks real similar to what you've posted here (because they don't sell marineland here in Australia anymore). Anyway cut it to a similar size and leaked a little but after a while it works real nice. I'm thinkin sliding a small cut of the original fill from the cart into the bottom so it soaks up the liquid and prevents the spillage. anyway, it's worked real so far, so for people who are thinking of trying this it's worth it! Get a lot more use out of you're e-liquid!