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Fish farm water moniotoring

Fish Farm water quality monitoring –

The Benefits of Continuous Automated Water Quality Monitoring

By Rick Petford, EnviroMonitors

Automated monitoring of water conductivity, dissolved oxygen and pH leads to improved feed ratios, minimises fish stress, and reduces fish disease and mortality. The net result is improved yields and reduced costs due to fish farm water quality monitoring.

Let’s look at each of the important chemical parameters and the specific effects they can have on your aquaculture operation.

Dissolved Oxygen

Low-dissolved oxygen levels are responsible for more fish kills, either directly or indirectly, than all other problems combined. High dissolved oxygen correlates with high biological productivity, and low dissolved oxygen means lower biological productivity.


pH is important in aquaculture as a measure of the acidity of the water. Fish cannot survive in waters below pH 4 and above pH 11 for long periods. The optimum pH for fish is between 6.5 and 9. Fish will grow poorly and reproduction will be affected at consistently higher or lower pH levels. Sensitive freshwater fish species such as salmon prefer pH levels between 7 and 8, becoming severely distressed and suffering physiological damage due to absorbed metals at levels below 6.

The Effects of pH on Warm-Water Pond Fish

pH        Effects on fish

4          Acid death point

4 to 5    No reproduction

4 to 6.5 Slow growth

6.5 to 9 Desirable range for fish reproduction

9 to 10  Slow growth

≥11       Alkaline death point

Source: Swingle 1969


Salinity events such as upwelling, rainstorm, and discharge can be detected with water conductivity sensor data loggers such as the cost-effective HOBO U24 002-C, which is ideal for measuring salinity, conductivity and temperature in saltwater environments with relatively small changes in salinity (±5,000 μS/cm). It can also be used to gather salinity data for salinity compensation of dissolved oxygen logger data.

About EnviroMonitors

EnviroMonitors is the environmental instruments division of Tempcon Instrumentation Ltd; established in 1980, specialising in instrumentation for measuring, controlling and logging: environmental and water variables. Clients include fish farms and aquaculture research projects across the UK and Ireland. The team will be happy to recommend and configure the ideal aquaculture monitoring equipment for your requirements. Call +44 (0)1243 558280, email: info@enviromonitors.co.uk, or visit www.enviromonitors.co.uk/aquaculture-water-monitoring/