NICO Blogs
Why Dawn Oxygen Matters on Thai Shrimp and Fish Farms
An afternoon measurement can make a pond appear well supplied with oxygen. Sunlight supports photosynthesis, and the surface may show a comfortable reading. Several hours later, conditions can be different as respiration continues through the night.
Fish, shrimp, microorganisms and aquatic plants consume oxygen. Decomposing feed and organic material add further demand. Without daylight photosynthesis, the balance can tighten, making the period around dawn especially useful for monitoring.
Warm water generally holds less dissolved oxygen than cooler water. Demand also changes as animals grow and feeding increases. A system that appeared sufficient early in a crop may need reassessment later. The relevant question is whether oxygen remains suitable where the stock is, through the most demanding periods.
Measurements should represent the pond rather than one convenient point. Compare depths, feeding areas, inlet and outlet zones. Record temperature, salinity, feeding, biomass, rain and existing equipment use alongside oxygen. Keep probes clean and calibrated so operating decisions are based on reliable data.
Nanobubble oxygenation can be evaluated as an additional delivery method. Air or oxygen is introduced through a compatible loop, with returns selected around circulation and demand. A high reading beside the return pipe is useful commissioning information, but it is not evidence of whole-pond performance.
Existing aerators may provide mixing and other essential functions. Do not remove them simply because a new device delivers oxygen. A trial should establish how the complete arrangement performs, including carbon-dioxide management where relevant.
Stock protection remains central. Define minimum operating conditions, alarms and emergency response before testing. Retain backup aeration and review the risk of excessive gas supersaturation for the species and life stage. Avoid introducing an unverified change across the entire farm at once.
The pilot should compare representative conditions, not a quiet day with a heavily loaded period. Oxygen stability may be an early endpoint; growth, survival and feed conversion require their own longer-term evidence. These outcomes also depend on health, nutrition and management.
For Thai farm operators, a useful starting point is a clear oxygen profile across the night and production cycle. It reveals whether additional delivery is needed and where it should be directed. That makes equipment selection and performance claims more credible.