Cartridge pumps save a lot of money over time and prevent a lot of headache. Mayfair/Johnson pumps are the most popular in my area. Great video and build! I am making a fully self contained tank right now and will be doing something similar. I am going with two pumps that will sit on top of my filter. One will have a spray bar and the other a venturi. Water will come in through slots on the bottom of the bulkhead so no stand pipe. I want my trash pickup as low as possible. Just to let people know, Flo-Rite makes fitting for anything livewell/bait tank in case you don't want to DIY pvc and fool with as much silicone and glue. They also have multiple styles of venturi. If you want to be even cheaper, you can make your own venturi like I plan on doing.

Great video, thanks , I need to build one of these!

30 or 50 gallon plastic drum cut to 2 piece about 7 inch wide how ever tall the cooler is for the 2 corner side of the cooler, 5200 to glue them into place, and for the other side cut 1 long piece to glue from side 2 side for the filter compartment then you can do the filter compartment how ever you want, easiest way is to do the filter socks, If your not a serious fishermen, you don't even need to fool with this, just buy you a 30 or 50 gallon plastic drum $10-15, cut 1/3 of the top off, trim the top for a lid, cut a door to dip bait and vola... no filter needed if your not a serious fishermen.

Did you seal Around the overflow?