Aquaculture

FA 0003B December 2014

Standard Operating Procedures Water Quality Management for Recirculating Aquaculture

Aeration with an airstone

Measuring water chemistry prior to feeding will help the farmer gauge the likelihood that fish are stressed. Sick and stressed fish will not eat feed and should not be fed in order to avoid water quality issues and mortality. Visually inspecting fish for external signs of disease such as lesions, dis-colored skin, and erratic swimming behavior should be done to prevent feeding stressed fish. If the water quality falls within the optimal range and fish appear to be disease free, the farmer should begin feeding by hand a small portion (handful) of the feed that the fish have been rationed.

METHODS (How to, How often, When, Where) Using a Hand-Held Water Quality Meter1. Remove the water quality meter

from its protective case.2. Plug in the appropriate probe

cable(s) for the desired parameter.3. Remove the protective probe

covers (if applicable).4. Turn on water quality meter.

Replace batteries if necessary.5. Calibrate the meter according to

the manufacturer instruction forthe desired parameter.

6. Insert probes into the fish culturetank and obtain parametermeasurement. Gently swing theprobes to get a steady reading.

7. Record the parameter measure- ment on the data sheet for each respective fish culture tank.8. Clean and sterilize probes between

fish culture units that do not sharea common water source.

9. Replace the protective probecovers.

10. Unplug probe cables.11. Store water quality meter in its

protective case.

Water ChemistryBecause precise water chemistry anal-yses can be expensive, it is preferable to use a less accurate testing method

more frequently than to have high ac-curacy with low frequency of testing. Trends in water chemistry are often more descriptive of water than a single data point.1. Obtain a clean sampling container

with a lid for each tank beingmonitored.

2. Label the sampling container forthe appropriate tank.

3. Submerge the sampling containerbeneath the surface of the waterand allow all air bubbles to escape.

4. Put the lid on the samplingcontainer while under water to

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Aquaculture

TASK FREQUENCYWater quality (D.O., pH, temperature) Daily to continuous

Critical water chemistry (ammonia, nitrite, alkalinity, carbon dioxide, chlorine)

Once to twice daily

Non-critical water chemistry (Hardness, Chloride, Nitrate) Once to twice weekly

Solids removal Continuous

Salinity manipulation As needed

Water treatments As needed

prevent any bubbles from entering the sample container. Note: If more than 1 hour will elapse before the sample water is processed, pack the samples on ice. Otherwise, depending on the analysis method, the sample may need to be acidified to preserve the current chemical parameters for later analysis.5. Process the water chemistry samples according to the instructions included in the testing kit. Note: If there are significant solids suspended in the sample, it may be necessary to filter the sample through a fine filter (less than 10 micrometers). This can be done with a glass fiber filter with a vacuum (Buchner) flask (triple rinsed with deionized water) hooked up to a vacuum pump. The filtered water collected in the flask may be used for chemical analysis.6. Record water chemistry data in hard copy and electronic format.7. Clean sample containers using soap and water, and rinse with distilled water three times.

Aeration

Water quality probe

Water chemistry spectrophotometer

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Aquaculture

…and justice for all The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or part of an individual’s income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA’s TARGET Center at 202-720-2600 (voice and TDD). To file a complaint of discrim-ination, write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue SW, Washington, DC 20250-9410, or call 800-795-3272 (voice) or 202-720-6382 (TDD). USDA is an equal opportunity provider and employer.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Cathann A. Kress, director, Cooper-ative Extension Service, Iowa State University of Science and Technology, Ames, Iowa.

AUTHORPrepared by D. Allen PattilloExtension aquaculture specialist, Iowa State University Extension and Outreach(515) 294-8616pattillo@iastate.eduwww.extension.iastate.edu/fisheries

PHOTO CREDITD. Allen Pattillo, Iowa State University, Iowa State University Extension and Outreach

TROUBLESHOOTING ACTION PLANLow Dissolved Oxygen

1. Provide aeration2. Provide supplemental oxygen3. Perform water exchange 4. Alert facility manager

Super-Saturated Dissolved Oxygen

1. Provide aeration2. Alert facility manager

High Ammonia Nitrogen

1. Perform water exchange2. Alert facility manager 3. Reduce temperature4. Reduce pH5. Add zeolite6. Aerate7. Add beneficial bacteria8. Add alkalinity9. Withhold feed

High Nitrite 1. Perform water exchange2. Alert facility manager 3. Reduce temperature4. Add NaCl salt (10 Cl- : 1 NO2

-)5. Add beneficial bacteria6. Add alkalinity

High Chlorine 1. Perform water exchange (with dechlorinated water)2. Aerate3. Add beneficial bacteria4. Alert facility manager

High Chloramine 1. Perform water exchange (with dechlorinated water)2. Add sodium sulfite or sodium thiosulfate3. Aerate4. Add beneficial bacteria5. Treat for ammonia6. Alert facility manager

High Temperature 1. Add chillers2. Add cool water3. Aerate4. Treat for low dissolved oxygen5. Alert facility manager

Low Temperature 1. Add heaters2. Add warm water3. Aerate4. Alert facility manager

High pH 1. Perform water exchange2. Monitor alkalinity3. Alert facility manager

Low pH 1. Increase alkalinity2. Perform water exchange3. Aerate4. Alert facility manager

High Solids Load 1. Clean filters2. Perform water exchange3. Treat for low dissolved oxygen4. Treat for ammonia5. Alert facility manager

High Salinity 1. Perform water exchange2. Alert facility manager

Low Salinity 1. Add salt2. Alert facility manager

Low Alkalinity 1. Increase alkalinity (add baking soda, agricultural limestone, etc.)2. Alert facility manager

High Carbon Dioxide 1. Aerate2. Perform water exchange3. Alert facility manager