01 · AquaGrow
What it is
Abrupt water changes can stress delicate hatchery stages. pH describes acidity; salinity is salt content, measured in parts per thousand (ppt). Check both the tank and the water being added.
Signs to watch for
- Swimming or feeding changes after a water event.
- Readings differ sharply from the tank’s recent trend.
- Several tanks sharing a water source become affected.
Common causes
- Replacement water differs from tank water.
- Heating, cooling or water-mixing control fails.
- Untested water or an unsuitable input is added.
How to confirm the cause
- Repeat temperature, pH and salinity tests with checked instruments.
- Compare source and tank readings with timed records; check DO as well.
What to do immediately
- 1
Stop unplanned additions and identify which water or control changed.
- 2
Maintain the safe, planned air supply and check animals and DO.
- 3
Call the technician with the readings, stage and recent changes. Do not rapidly reverse the change or add acid, lime or salt by guesswork.
- 4
Follow a gradual, stage-specific correction plan and retest as directed.
Prevention: your practical checklist
- Test and match replacement water before use.
- Keep mixing, temperature and alarm equipment maintained.
- Record water additions and stage-specific operating limits.
When to call an expert
- Treat rapid losses or breathing distress after a water change as an emergency.
- Seek help for unstable readings or unexplained differences between tanks.
Farmer questions
Is a later normal reading enough?
No. A short-lived shock may be missed by a later reading. Record the event, instrument checks and animal response, and investigate other causes too.
Should I restore the old salinity immediately?
Another sudden change may add stress. Use a technician-led adjustment based on the actual readings and life stage.
Are pond targets suitable for all hatchery tanks?
No. Broodstock, larvae, live feed and transport systems need separate operating plans. Do not apply the library’s grow-out reference panel to them.
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.
- SHAPHARI hatchery operating guidelines — production, biosecurity and records ↗MPEDA; linked guideline, not AquaGrow certification or a legal-compliance audit
- Hatchery operations and assessment framework (2007) ↗FAO FTP 446; historical P. monodon manual, not a vannamei treatment protocol