Don't know about 104, but I'm using the 204. It works extremely well for me and if you place the water intake in the opposite side then the waterfall then your water will be crystal clear... and the entire water area will be circulated. If you place is next to the waterfall, the far sides will be a bit staggnant.
Mine is crystal brownish water , because I removed the charcoal and I'm running peat granules with amonia remover and foam. It's been running for about a year now 24/7
I also add black water extract to my water every now and then.
Would this filter/pump be good enough to use with a tank to support a water fall.