Mom, I think you probably negated a significant swing also by doing half, waiting a few weeks for the bacteria to get where it needed to be before doing the other half. By then the rest of your system had already compensated. Besides, with the sand, rock and HOB your bioballs probably only took care of what 20% to 30% filtration for your system? If those numbers are right, using your method you only reduced capability by 10-15%.

Just thinking out loud of course.