I have plans for a 180 sqft garden pond (2225 gallons) with an 64sqft bog. The plan is to keep koi, turtles and ducks. Ducks poop a lot but my experience with domestic ducks has shown they actually spend most of the time out of the water and doing their pooping on the patio. My question is do you think I need a settlement chamber? I plan on running 4000gph so from what I've read a 400 gallon SC would be the minimum size. I plan to use the aquablox system and I'm wonder if that space serves as a SC? If so, then would it make a difference using the large blox as opposed to the small ones?