... they are far more self cleaning than a round tank could ever be.
I couldn't disagree more JKB and so does Dr. Timmons, Dr. Ebeling, or Dr. Summerfelt, three of the biggest names in RAS' but hey we don't always agree do we JKB?
The engineering I've seen to effectively keep clean rectangular and raceways systems with all the plumbing is beyond most people that are starting out.