Page Banner

United States Department of Agriculture

Agricultural Research Service

Title: Reducing Weigh-backs with Liquid Oxygen

Authors
item Torrans, Eugene
item Hogue, JR., C - MSU EXTENSION SVC.
item Pilkinton, S - PILKINTON BROS. FARMS

Submitted to: NWAC (National Warmwater Aquaculture Center) Aquaculture Newsletter
Publication Type: Popular Publication
Publication Acceptance Date: November 1, 2002
Publication Date: December 1, 2002
Citation: Torrans, E.L., Hogue, Jr., C.D., Pilkinton, S. 2002. Reducing Weigh-backs with Liquid Oxygen. NWAC (National Warmwater Aquaculture Center) Aquaculture Newsletter. 5(2):10-11.

Interpretive Summary: Every catfish farmer has a horror story about losing thousands of pounds of food fish being held in a sock prior to sale to a processor. This article describes equipment that can reduce these fish losses. We designed and built a small single-axle trailer to hold three 50-gallon liquid oxygen tanks. The unit is small enough to be moved around a commercial channel catfish farm with a pickup truck or small tractor. It is being used successfully to provide supplemental oxygen at remote on-farm locations to channel catfish that are being held in a sock (net cage or live car) at high density prior to sale. The total cost of the complete sock-saver with trailer, liquid oxygen tanks, pressure/flow regulators and diffusers was $8400. It is simple to operate, durable and virtually maintenance-free. Since it does not require any electrical or mechanical power source, it can be set up anywhere. The small "footprint" of the trailer does not interfere with the other equipment normally used when loading fish from a sock. Individual flow regulators allow use of one, several or all eight diffusers as needed. The diffusers and hoses are self-weighted, tangle-free, and do not interfere with the normal process of crowding the fish in the sock and dipping them up in the loading basket. The unit can increase dissolved oxygen in a sock by as much as 0.9 mg/L for a cost of approximately $30.00 a night.

Technical Abstract: A small single-axle trailer was designed and built to hold three 50-gallon liquid oxygen dewars. The unit is small enough to be moved around a commercial channel catfish Ictalurus punctatus farm with a pickup truck or small tractor. It is being used successfully to provide supplemental oxygen at remote on-farm locations to channel catfish that are being held in a net sock at high density prior to sale. The total cost of the complete sock-saver with trailer, dewars, pressure/flow regulators and diffusers was $8400. It is simple to operate, durable and virtually maintenance-free. Since it does not require any electrical or mechanical power source, it can be set up anywhere. The small "footprint" of the trailer does not interfere with the other equipment normally used when loading fish from a sock. Individual flow regulators allow use of one, several or all eight diffusers as needed. The diffusers and hoses are self-weighted, tangle-free, and do not interfere with the normal process of crowding the fish in the sock and dipping them up in the loading basket. The unit can increase dissolved oxygen in a sock by as much as 0.9 mg/L.

Last Modified: 9/10/2014
Footer Content Back to Top of Page