This is an extremely interesting topic for me. How/where do you plan on fitting the heater into the AC Mini?
Haven't done it yet. Options are to place it vertically (would need to cut out a corner of the sponge filter at the bottom) or horizontally such that it lays on the impeller cover then extends into / across the filter basket (would need to cut a notch in the basket).
Leaning toward the latter as I want to avoid any bypass of the sponge and this would also place the heater close to my bio media (nitrogen processing bacteria like heat supposedly).
Will post more pics when I get around to this.