In aquaculture, success is often determined by a single invisible factor: dissolved oxygen (DO). Whether you manage fish ponds, shrimp farms, hatcheries, or high-density recirculating aquaculture systems (RAS), maintaining proper DO levels is essential for animal health, water quality, and overall production efficiency.
This article explains the importance of dissolved oxygen in aquaculture, how low DO affects aquatic systems, and why reliable DO monitoring instruments—such as the ERUN-SP7-A5 Portable Dissolved Oxygen Meter—are indispensable for achieving stable and profitable operations.
Dissolved oxygen refers to the level of free oxygen molecules present in water. Measured in mg/L (or ppm) and sometimes expressed as oxygen saturation (%), DO is vital because fish, shrimp, mollusks, and other cultured organisms rely on it for respiration. Unlike terrestrial animals, aquatic species extract oxygen through gills, meaning even slight fluctuations in DO have immediate physiological effects.
Extensive aquaculture studies show that DO is one of the most critical water quality parameters. Adequate DO supports:
Efficient metabolic function
Strong immune systems
Optimal feed intake and conversion
Faster growth rates
Higher survival and improved harvest yields
When DO levels fall below species-specific thresholds, animals experience stress, reduced feeding, slower growth, and in severe cases, mass mortality events. Low DO also makes stock more susceptible to bacterial and parasitic infections.
On the other extreme, excessively high DO—often from uncontrolled photosynthesis or supersaturated water—may lead to gas bubble disease.
Most aquaculture species perform best with DO levels above 5 mg/L, though high-density systems or sensitive species may require even higher concentrations. Maintaining DO within recommended ranges can dramatically improve productivity and reduce operational risks.
Dissolved oxygen is not only critical for aquatic animals but also for the overall health of the water environment. Aerobic bacteria depend on oxygen to break down organic waste, leftover feed, and fish excreta. When DO drops, aerobic decomposition slows, causing waste accumulation and the development of anaerobic zones.
These anaerobic pockets produce harmful by-products such as hydrogen sulfide (H₂S), methane, and ammonia—substances that directly endanger aquatic animals and deteriorate water quality.
Low DO is one of the fastest triggers of stress in aquaculture species. Stress weakens the immune system, making fish and shrimp more vulnerable to pathogens. High ammonia and nitrite levels—often linked to low DO—further compromise health, causing gill damage and slowed metabolism.
Maintaining sufficient DO helps stabilize the production environment and reduces disease outbreaks, which is crucial in intensive operations.
Oxygen availability has a direct impact on feed utilization. When DO levels are optimal:
Appetite increases
Feed conversion ratio (FCR) improves
Energy is directed toward growth instead of stress management
In contrast, low DO reduces feeding efficiency and delays harvest cycles, increasing production costs.
Historically, operators relied on methods such as the Winkler titration or early-generation electrochemical probes. While accurate, these methods can be time-consuming, require chemical reagents, or demand frequent membrane replacement.
Modern DO testing devices provide fast and accurate results that support real-time decision-making. Portable meters are especially valuable because aquaculture environments require frequent, on-site measurement across ponds, tanks, and water circulation systems.
The ERUN-SP7-A5 is engineered specifically for rapid, high-precision water quality testing. Key features include:
Stable, high-precision measurement of DO concentration (mg/L or ppm), saturation (%), and temperature (°C)
Advanced optoelectronic technology for reliable readings
Dedicated dissolved oxygen electrode for fast response and long-term stability
One-hand operation, ideal for field technicians and daily pond checks
Versatility across aquaculture, environmental monitoring, laboratories, and industrial applications
For aquaculture operations, the SP7-A5 provides actionable data that allows managers to adjust aeration, feeding, and water circulation before problems occur.
DO levels fluctuate throughout the day—typically lowest at dawn due to plant and algae respiration. Farmers should measure DO multiple times daily, especially:
Early morning
After feeding
During algae blooms
In high-temperature periods
In high biomass conditions
Portable meters like the SP7-A5 help catch dangerous low-oxygen periods early.
Maintaining strong water movement increases oxygen transfer and prevents dead zones. Aerators, paddle wheels, blowers, and diffusers should be adjusted based on DO readings to balance energy cost and water quality.
Overstocking and overfeeding dramatically increase oxygen demand. Pairing DO monitoring with good waste management helps prevent low DO events.
Real-time measurements from the ERUN-SP7-A5 help operators:
Adjust aeration before DO drops dangerously
Optimize feeding schedules
Plan water exchange
Prevent stress and disease
Reliable DO tracking leads to more predictable yields and lower mortality.
ERUN instruments are developed for real-world conditions—portable, durable, and easy to operate in outdoor aquaculture environments. The SP7-A5 ensures precise, repeatable measurements needed for modern farm management.
In addition to dissolved oxygen, ERUN provides a full range of water quality testing instruments, supporting parameters crucial for aquaculture health.
Consistent, accurate DO monitoring reduces risks, stabilizes water quality, and supports healthier, faster-growing stock—allowing aquaculture businesses to maximize production while reducing losses.
Dissolved oxygen is one of the most important parameters in aquaculture. It affects the health of aquatic animals, feed efficiency, disease prevalence, and overall water quality. Maintaining adequate DO levels is essential for any successful aquaculture operation.
With precise and portable tools like the ERUN-SP7-A5 Portable Dissolved Oxygen Meter, farmers can quickly measure DO, respond to changes in real time, and ensure optimal conditions for growth and survival.
To explore more advanced water quality meters and testing solutions, visit erunwas.com.
