not planning on it,just seems like you could somehow...maybe a cutting a hole in the bottom,or on the side a little higher up so it does'nt lose its suction or whatever by the water level inside the HOB dropping too low.....
Modifying a HOB is complicated and it can loose prime easily. You can use the case for the reservoir and add your own piping but it gets sloppy. If it's all you got to work with, go for it.