I've had my BK 250 internal for 10 years. I just replaced the old pump with a new RD Speedy 50 watt DC pump. Works great and only goes to prove once again you get what you pay for. I got a decade of use from the old one.
The funnell you see on top of the skimmer is there to vent the exhaust outside. I do this because I use ozone and it also helps to keep the humidity down in my basement which is where my sump is located. You can also see the cup and tray the skimmer effluent pours into after it exits the skimmer. There is a carbon pad layered on the tray and again this is because I use ozone.
Here is the latest video of my tank. It is a year and a half old now.
https://youtu.be/OXlnNycoiJ0
Here is tour of the entire sump and fish room.
https://youtu.be/qvKTg663RTo