What salinity range is safe for brackish-water shrimp?
Vannamei is the most salinity-tolerant commercial shrimp — cultured from 0.5 ppt inland ponds to 40 ppt coastal ponds. But the acclimation window matters as much as the target. A 5 ppt shock kills PL faster than the wrong absolute salinity.
Vannamei: 5–35 ppt (optimal 15–25 ppt). Monodon: 10–30 ppt (optimal 15–25 ppt). Never change salinity more than 3 ppt per day. Below 5 ppt vannamei, supplement with KCl and MgCl₂ (potassium and magnesium) — inland pond water is usually deficient.
Step-by-step
- 1
Measure at three depths, not just the surface
Post-monsoon or after heavy rain, freshwater layers on top. Surface can read 8 ppt while the bottom is 20 ppt — enough to shock benthic shrimp.
- 2
Acclimate PL slowly at stocking
Match hatchery salinity within 2 ppt at stocking. Then adjust the pond by 1–2 ppt per day over 5–7 days to reach the target grow-out salinity.
- 3
Test K⁺ and Mg²⁺ for low-salinity culture
Below 5 ppt, inland source water is usually depleted. Target: K⁺ ≥ 100 mg/L, Mg²⁺ ≥ 350 mg/L, Na:K ratio 28:1. Supplement with muriate of potash and magnesium chloride.
- 4
Manage monsoon dilution
Heavy rain can drop salinity 5 ppt in one night. Delay feed for 6 hours, run aerators to mix layers, and add sea-salt (25 kg per 1000 m³ per ppt) if the drop exceeds 3 ppt.
- 5
High-salinity endpoint
Above 35 ppt, growth slows and stress mortality rises. Refill with lower-salinity water or wait for rainfall. Never exceed 40 ppt for vannamei.
- 6
Track salinity daily on a chart
Trends matter more than single readings. A slow 5 ppt drop over 10 days is normal for a monsoon pond; a 5 ppt drop in one day needs intervention.
When to call a technician
- Salinity swing of 5 ppt or more in 24 hours.
- PL mortality within 72 hours of stocking with correct water parameters.
- Soft-shell shrimp at any DOC — usually a K⁺ or Mg²⁺ deficiency, not salinity itself.
- White-spot (WSSV) suspicion — WSSV outbreaks are salinity-swing triggered.
How CAMARON handles this automatically
CAMARON's salinity acclimation calculator plans the day-by-day pond salinity ramp from hatchery to grow-out target. Monsoon rainfall triggers auto-warnings from the Sentinel Hub feed and cross-checks against your salinity log to flag stratification risk.
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