A vessel holding water is called a tank. However, just because a vessel holds water does not necessarily make it a good fish rearing habitat nor does it necessarily make it efficient for the operator to manage. Of all the aspects of modern aquaculture that researchers have studied, none has been more over looked than the size and configuration of the very vessel that the growing product has to call home until it is ready for market. We at Global Aquatics have never understood why people pay so little attention to this important part of a system design, especially since we have spent so much time developing what we consider to be the perfect design when efficiency and
management are considered.

Small verses Large:

It is very important to remember that as a fish farmer you must manage two things at the same time, water quality and the fish. Obviously the less water you have right in front of you in a vessel, the easier it is to manage. there will be more positive water exchange from the inflow and less dilution. Thereby allowing for better water quality.

It also goes without saying that the more accessible the animals are to you the easier they are to manage as well. By managing the animals we are referring to the need to constantly sort the larger faster growing ones from the population at certain intervals during the growth process. This means that every so often the entire population of the tank must be separated into other tanks based on the size of the individual animals. The reason for needing to do this is because as in all animal populations a pecking order occurs whereby the larger, more aggressive animals dominate the rest of the group.
When these dominate animals are removed from the tank and placed with others their same size, a new pecking order will develop within the the remaining population. It is because grading a pond is not possible that there is such a variation in growth sizes at harvest time. When grading a tank the faster it is accomplished the less stress is placed on the fish. When you have a large tank containing 25,000 or more animals it may not even be possible to grade this group and if it is attempted it will likely place some of this group under stress for as much as seven times the amount time it would take to grade
the group in the smaller tank. Grading the fish is also a requirement for harvesting. Generally in an intensive system the fish are harvested on a continuous basis as they become market ready. Since we know that some of the fish will grow much faster than the others, it is necessary to be able to capture just the ones that are market size from a huge tank of ungraded animals without injuring the smaller that still need more growth time.