So I just got my SunSun 403b and installed it on my 36g bf this past weekend. I can already tell that the water is much clearer and the fish seem to like the current (especially the oto's. they seem to like to hang out on top of the spray bar). I have mechanical filter's in the bottom, and 2 rows of bio filter (one has rings and bioballs, the second has matrix). This is just a general question. How does this canister actually filter the water? I have no doubt it's working as I can see a difference but how? I know how mechanical/bio/chemical filtration works...but when I put this filter together, what is causing the water to pass through all 3? It seems the water gets sprayed into the canister at the lid, and then the lid sucks it back up...how does the water get all the way through the 3 layers and not just picked right back up from the top? Does that make sense? I've looked online and all sunsuns are like this as well as many other filters. I'm not missing any pieces. I hope this makes sense.