Water Quality Deep Dive

Dissolved oxygen management in shrimp & fish ponds

Why overnight DO crashes are the #1 cause of mass mortality, and the aeration + monitoring routine that prevents them.

Updated July 11, 2026

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Why DO is the #1 killer

Dissolved oxygen (DO) is the single most important water-quality parameter in aquaculture. Overnight DO crashes cause more mortality than disease in shrimp ponds, and a full crash can kill a standing crop in six hours. Every management decision — stocking density, feeding rate, aeration sizing — traces back to how much oxygen the pond can hold.

Safe DO ranges by species

  • Vannamei shrimp: keep DO above 4 mg/L, act at 3 mg/L.
  • Monodon (black tiger): 4.5 mg/L minimum, less tolerant of dips.
  • Tilapia: 3 mg/L minimum, 5+ mg/L for optimal growth.
  • Carp / catfish: tolerate 2 mg/L briefly, target 4 mg/L.

The diurnal oxygen cycle

Photosynthesis produces oxygen through the day; respiration by shrimp, fish, algae and bacteria consumes it 24/7. DO typically peaks at 15:00 and bottoms at 05:00. The wider the swing, the higher the risk — a pond that hits 12 mg/L in the afternoon is nearly always the same pond that drops below 3 mg/L at dawn.

Aeration strategy and sizing

Aerators do two jobs: add oxygen and circulate water. Paddlewheels are cost-effective for surface exchange; diffusers deliver oxygen at depth. Size aeration to standing biomass, not stocking density — a DOC 90 pond needs 3× the aeration of a DOC 30 pond at the same stocking.

Monitoring: manual vs continuous

Manual dawn checks catch yesterday's crashes. Continuous IoT probes catch tonight's, with a predictive alert when DO drops below 4 mg/L and is still falling. CAMARON's alert engine fires WhatsApp + in-app notifications so the pump switches on before the shrimp start swimming at the surface.

Emergency response to a DO crash

  1. Turn on every available aerator, including emergency backup.
  2. Add hydrogen peroxide (H₂O₂) at 1–2 mg/L as a rescue oxidant.
  3. Halt feed for the next 24 hours; feeding raises oxygen demand.
  4. Once DO stabilises above 4 mg/L, resume at 50% ration and investigate the trigger.

Get alerts before the parameter breaches lethal levels.

CAMARON's 7-parameter alert engine watches DO, pH, temperature, salinity, TAN, nitrite and turbidity — species- and life-stage-aware. First pond is free.

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