Be careful of the vacuum effect. When the hose/pipe starts to go down into the sump, have a loose fitting hose or pipe that goes down into the sump. That way, there is no airtight fit and subsequent vacuum back into the reservoir.
See the vertical PVC
pipe in the middle of the pic? Look at the red thingy. Just below it there is a 1/2 elbow. It sits on a big hose that doesn't fit airtight.
Now, I haven't run this yet but I'm hoping for two things. 1) no vacuuum sucking my fuge/sump water back into the reservoir, and 2) no water noise from the reservoir water dropping into the fuge/sump. The loose hose sits on the bottom of that chamber.