Submitted to: North American Journal of Aquaculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/10/2009
Publication Date: 6/1/2010
Citation: Mitchell, A.J., Farmer, B.D. 2010. Evaluation of an ultra low-flow water delivery system for small experimental tanks. North American Journal of Aquaculture. 75:195-200. Interpretive Summary: Certain fish disease challenge and treatment studies require very low water exchange rates, one to four water exchanges per day, 10 gallons or less. Low exchange rates can be easily produced in large tanks but with extreme difficulty in small volume tanks and aquaria. Researchers at the Harry K. Dupree Stuttgart National Aquaculture Research Center developed an ultra low-flow system that consistently delivers very small quantities of water (as low as 2 gallons per day) as a water supply for small aquaria studies. The ultra low-flow system is comprised of a semi-enclosed header tank with a variable standpipe height and dulled, guarded syringe needle nozzles. Testing showed that the system was a safe, reliable and precise system. The use of this system in small tanks will greatly reduce the amount of pathogenic biological materials and the number of research animals needed to perform studies.
Technical Abstract: An ultra low-flow water delivery system was developed and tested for use in research studies requiring low-flow in small water volumes. Small test systems save on the amount of fish, chemicals, and biologics needed in disease challenge and treatment experiments. The ultra low-flow system, comprised of a semi-enclosed header tank with a variable height standpipe and dulled, guarded syringe needle nozzles, can produce flows that result in 1 to 20 water exchanges per day for a 10 L volume. Water was pre-filtered through two inline 70µm-filters to limit flow loss due to particulates blocking the small orifice nozzles. Accurate and precise flows are produced by the system and needle nozzles should last at least seven days before fouling requires them to be changed; nozzle changes can be made in about 5 seconds. Flows in the range of 5 to 135 mL/min were produced by using 3.8 cm long, 16, 18, 20, and 21 gauge needles with standpipe heights of 15.2 cm, 30.5 cm, and 45.7 cm. Water flows through selected needle nozzles and standpipe heights varied =5% over a 7-d period. This ultra low-flow system provides a practical, inexpensive, and precise, water-delivery system that should have multiple usages for fisheries research.