Well initially practiced in central drain shrimp maturation tanks where a circular current was introduced into a round tank and where solid fecal waste from shrimp tendered to accumulate in the center of the tanks whence siphoned out manually.
With intensification in grow-out automatic solid waste removal management becomes a more important part of maintaining quality husbandry conditions. Sludge (made up of shrimp wastes but also uneaten feed) build up has always been of concern.
Here is an interesting oversight
