01 · AquaGrow
What it is
Dissolved oxygen (DO) is oxygen in the water that shrimp use to breathe. A shortage can become an emergency. Signs alone are not enough: check with a working DO meter.
Signs to watch for
- Shrimp move to the surface or pond edges.
- Feeding falls and shrimp become weak.
- Problems appear at night, before sunrise or after cloudy weather.
Common causes
- Aeration cannot meet the oxygen demand of the crop and pond.
- A power outage stops aerators.
- A dense algal bloom dies or organic waste uses up oxygen.
How to confirm the cause
- Use a calibrated DO meter at several locations and depths; record the time and temperature.
- Check the aerators and electricity supply. Do not enter the water to investigate equipment.
What to do immediately
- 1
Start or increase safe mechanical aeration; use backup power if needed. Keep people away from live electrical equipment.
- 2
Pause feeding while shrimp are distressed and oxygen is low. Do not add fertiliser or oxygen-demanding inputs.
- 3
Recheck DO as aeration operates. Arrange urgent technical help if shrimp remain distressed or DO does not recover.
- 4
Record readings and losses. Plan any water exchange with a technician using tested, suitable reservoir water; do not pump in unknown canal water.
Prevention: your practical checklist
- Measure DO before sunrise and check more often during high biomass, cloudy weather and bloom changes.
- Test backup power and maintain aerators. Match aeration capacity to the crop with a technician.
- Use feed trays and records to limit waste.
When to call an expert
- Call urgently for surface crowding, new deaths, or DO below 4 ppm. Do not wait for a second reading if shrimp are in distress.
- Get help if oxygen repeatedly falls despite working aeration.
Farmer questions
What DO reading should I aim for?
MPEDA grow-out guidance lists 4–6 ppm. Aim for a margin above 4 ppm, commonly 5 ppm or more, rather than operating at the lower edge. Required aeration depends on the crop; shrimp distress needs action at any reading.
Does clear water mean enough oxygen?
No. Water appearance cannot measure DO. Use a working meter at representative locations and depths.
Will a probiotic fix an oxygen emergency?
Do not rely on a product instead of aeration. Restore oxygen and have the cause checked before adding inputs.
Sources & further reading
AI-assisted educational content and translations, source-checked 17 October 2026. Not an individual diagnosis or prescription. Independent aquaculture-health and native-language specialist approvals have not been supplied. Sources do not endorse AquaGrow.