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Emergency Critical

Why Are My Shrimp Dying?

Comprehensive triage guide for unexplained shrimp deaths. Learn to identify the cause and take immediate action to save your remaining colony.

Affects: All Shrimp

Quick Answer

First, test your water immediately for ammonia, nitrite, and nitrate. If ammonia or nitrite is above 0, do an emergency 25% water change with temperature-matched, dechlorinated water. Check for any recent changes: new decorations, medications, fertilizers, or water changes. Remove any dead shrimp immediately to prevent further contamination.

Symptoms to Look For

Check if your shrimp are showing any of these symptoms. Symptoms are grouped by severity to help you assess the situation.

Early Warning

  • Shrimp appearing lethargic, not grazing

    Visual: Staying still, not moving around tank

Moderate

  • Shrimp swimming erratically or 'darting'

    Visual: Sudden frantic swimming, hitting glass

  • Shrimp clustered near water surface or filter outflow

    Visual: Gasping behavior indicates low oxygen or toxins

  • Loss of color or cloudy/milky appearance

    Visual: Normally vibrant shrimp looking pale or opaque

Severe

  • Shrimp found dead on tank bottom or filter intake

    Visual: Motionless, may be pink/red or cloudy

  • Multiple deaths over a short period (hours to days)

    Visual: Finding 2+ dead shrimp within 24-48 hours

Does this match what you see? If your shrimp are showing multiple severe symptoms, act immediately. Early symptoms give you more time to correct the issue.

Possible Causes

Causes are listed by likelihood. Start with the most common causes and work your way down.

#1

Ammonia or Nitrite Spike

Common

Toxic nitrogen compounds from fish waste, uneaten food, or dead organisms. Even small amounts are lethal to shrimp. Common in new or uncycled tanks.

How to identify:

Test water with API Master Test Kit or similar. Any reading above 0 ppm for ammonia or nitrite is dangerous.

#2

Copper Exposure

Common

Copper is extremely toxic to invertebrates, even in trace amounts. Sources include medications (ich treatments), copper pipes, cheap heaters, and some fertilizers.

How to identify:

Check if any medications, fertilizers, or new equipment was added. Test for copper if suspect - even 0.03 ppm can be lethal.

#3

Chlorine/Chloramine in Water

Common

Tap water contains chlorine or chloramine that kills shrimp instantly. Can occur from forgetting to dechlorinate during water changes.

How to identify:

Did you recently do a water change? Did you use dechlorinator? Chloramine requires specific treatment - not all dechlorinators handle it.

#4

TDS or Parameter Shock

Common

Sudden changes in water parameters (TDS, pH, temperature) cause osmotic stress. Often occurs after large water changes or improper acclimation of new shrimp.

How to identify:

Test TDS before and after water changes. Changes greater than 20-30 ppm can cause stress. New shrimp should be drip acclimated for 1-2 hours.

#5

Low GH / Mineral Deficiency

Possible

Insufficient calcium and magnesium for molting. Causes failed molts and eventually death, especially in soft water areas.

How to identify:

Test GH. Neocaridina need GH 6-12, Caridina need GH 4-6. Also check for white ring of death symptoms.

#6

Disease or Bacterial Infection

Possible

Bacterial infections can spread through a colony, especially in stressed or weakened shrimp. Often secondary to poor water quality.

How to identify:

Look for pink/red discoloration, cloudy patches, lesions, or unusual spots. Infected shrimp are often lethargic.

#7

Pesticide Contamination

Possible

Pesticides from plants, hands (bug spray, lotions), or household sprays. Extremely toxic to invertebrates.

How to identify:

Did you add new plants without quarantine? Touch tank after using products? Use bug spray near tank?

#8

Old Age

Possible

Shrimp naturally live 1-2 years. If deaths are gradual and limited to larger/older individuals, it may be natural.

How to identify:

Are only large, mature shrimp dying? Are juveniles healthy? Natural deaths are gradual, not sudden mass die-offs.

#9

Predation

Rare

Fish or other tank mates attacking and killing shrimp. Shrimplets are especially vulnerable.

How to identify:

Check for signs of injury on dead shrimp. Observe tank at night when predators may be more active.

#10

Oxygen Depletion

Rare

Low oxygen from overstocking, high temperature, or poor circulation. More common in summer or heavily planted tanks at night.

How to identify:

Shrimp gasping near surface or filter outflow. Check temperature (high temps = less dissolved oxygen). Add airstone.

Solutions

Option 1: Immediate Emergency Response

Take action within 1 hour of discovering deaths
If caught early and cause identified, 60-80% can prevent further deaths

Do not add medications unless you have identified a specific disease - many medications contain copper

  1. 1

    Test water parameters immediately

    Test ammonia, nitrite, nitrate, pH, and TDS. Write down all values. This is your first diagnostic step.

    Do not skip this step - you cannot treat what you cannot measure

  2. 2

    Remove dead shrimp

    Dead shrimp decompose quickly and release ammonia. Remove all bodies immediately to prevent further water quality degradation.

  3. 3

    If ammonia or nitrite > 0, do emergency water change

    Change 25-30% of water with temperature-matched, dechlorinated water. Make sure new water TDS is within 20 ppm of tank water.

    Do not change more than 30% at once - large changes cause additional stress

  4. 4

    Add activated carbon

    If you suspect toxins (copper, pesticides, medications), add fresh activated carbon to the filter. It will absorb many contaminants.

  5. 5

    Increase aeration

    Add an airstone or point filter output at surface to increase oxygen. Stressed shrimp need more oxygen.

Recommended Products

API Master Test Kit Seachem Prime Activated Carbon TDS Meter

These are informational recommendations only. Not affiliated with any brands.

Option 2: Investigation and Root Cause Analysis

Thorough investigation over 24-48 hours
Identifying root cause prevents future deaths
  1. 1

    Review recent changes

    Write down anything that changed in the last 1-2 weeks: water changes, new additions (plants, decor, fish), feeding changes, room changes (sprays, cleaners).

  2. 2

    Check equipment

    Inspect heater for damage (can leach metals), check filter is running properly, verify thermometer accuracy.

  3. 3

    Test source water

    Test your tap/RO water for ammonia, pH, TDS. Some tap water seasonally contains ammonia or chloramine changes.

  4. 4

    Observe surviving shrimp

    Watch for symptoms: erratic swimming, lethargy, color loss, not eating. Document what you see.

Prevention Tips

Follow these practices to help prevent this problem from occurring in the future.

  • Always fully cycle your tank before adding shrimp - ammonia and nitrite must read 0 ppm consistently
  • Use a dechlorinator that handles both chlorine AND chloramine (like Seachem Prime)
  • Test your water weekly and log parameters to spot trends before they become problems
  • Never add medications to a shrimp tank without verifying they are invertebrate-safe
  • Quarantine new plants for 2-4 weeks or treat with alum dip to remove pesticides
  • Keep water change size to 10-15% weekly rather than large infrequent changes
  • Match new water temperature and TDS to tank water before adding
  • Wash hands thoroughly before putting them in the tank
  • Never use copper-based medications or fertilizers in shrimp tanks

Related Parameters to Monitor

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Frequently Asked Questions

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