The filter is built into the top of the tank. It uses a powerhead pump to push water through the spray bar above the filter media on the left then as you have said flows to the right then out through two outlets.. not sure why but one has a "nozzle" and the other just dumps straight down into...
Tiny Tims Adventures is a good one for a laugh. I also follow
Beyond The Press - If you like things being crushed
EricTheCarGuy - If you like cars and fixing them
TheBackyardScientist - If you're into blowing things up etc
CycleCruza - if you're into motorbikes
I've been reading through the forums about building your own filters etc and I don't really fancy spending 20-30 on a set of cartridges when I could spend the same amount and have something that will last me far longer!
This is the current setup. It seems silly having a cartridge on the second...