cascading water fall from one sump to another

I recently saw at a LFS with african cichlids in about 4 to 5 aquariums which were all connected to a series of sumps behind.They was even a protein skimmer, and water freely falling like a water fall from one sump to an another and a strong pump sending back water to the tank from the last sump. the guy at that LFS said that oxgenation will increase a lot with a series of water fall sump which is great for beneficial bacteria growthy within the media in the sump. I have yet to read any forum here about a waterfall inside a series of sumps or even within one compartment of a sump to another.Can any one give a few tips and light on this.Is there any on you tube about waterr fall sump?

Many people use air stones in their sumps to ad oxygen. I air my system considerably before the return to the tank. I have little with filtration, just roots.

Most people put a bunch of bioballs in their sump to accomplish the same thing.
Water hits bioballs, breaks into many droplets, CO2 released, oxygen absorbed. Plus the bioballs are a great media for beneficial bacteria to grow (converting ammonia/nitrite to nitrates).
I'd recommend doing that instead, unless you want a waterfall to look at for decorative purposes.

Anyone with a sump has a waterfall due to the water flowing down the drain line to the sump. Additionally a drip tray also adds to the water fall effect with all benefits mentioned in the first post minus the headaches/complexities of dealing with multiple sumps.