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
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Shrimp ignore prepared food completely
Visual: Food pellets/wafers remain untouched for hours
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Shrimp approach food but don't eat
Visual: Shrimp investigate then walk away from food
Moderate
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Sudden change from eating enthusiastically to ignoring food
Visual: Previously eager feeders now showing no interest
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Shrimp not grazing on surfaces either
Visual: No foraging behavior, just sitting still
Severe
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Shrimp hiding and refusing all food types
Visual: Combined with lethargy and seclusion
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.
Abundant Biofilm (Normal)
In mature tanks, shrimp constantly graze on biofilm - the microscopic organisms coating all surfaces. If biofilm is plentiful, they simply aren't hungry for prepared food.
Are shrimp actively grazing on glass, plants, wood, and substrate? If they're constantly 'picking' at surfaces, they're eating biofilm. This is healthy behavior.
Overfeeding - They're Full
Many keepers overfeed. If shrimp have access to more food than needed, they become selective and may ignore new offerings. Shrimp can go days without prepared food.
How often do you feed? Is there leftover food hours after feeding? Do you feed daily? Shrimp in established tanks need prepared food only 2-3x per week.
Food Preference
Shrimp have preferences and may ignore certain foods. They often prefer biofilm and algae over commercial foods. New foods may be ignored until they try them.
Have you tried different foods? Some shrimp prefer vegetables, others prefer protein. Try blanched zucchini, spinach, or different commercial brands.
New Tank / Recent Stress
Recently added shrimp or those recovering from stress may not eat for days. This is normal acclimatization behavior - they're prioritizing survival and exploring over eating.
Are shrimp new (within 1-2 weeks)? Any recent stressors like water change, moving, or shipping? Give them time to settle.
Pre-Molt Behavior
Shrimp often reduce feeding before molting. This is normal and they'll resume eating after successfully molting.
Does the shrimp look slightly pale or swollen? Reduced activity before molting is normal. They'll resume eating after molt.
Poor Water Quality
Shrimp under stress from ammonia, nitrite, or other water quality issues may stop eating. This is usually accompanied by other symptoms like lethargy or hiding.
Test parameters. If shrimp are also hiding, inactive, or showing color changes alongside not eating, investigate water quality.
Illness
Sick shrimp often stop eating. However, illness is accompanied by other symptoms - lethargy, color changes, isolation, or visible problems.
Is the shrimp active? Good color? Swimming and exploring? If only symptom is not eating prepared food while otherwise healthy, illness is unlikely.
Solutions
Option 1: Assess If There's Actually a Problem
- 1
Observe grazing behavior
Watch your shrimp for 10-15 minutes. Are they actively picking at surfaces? Moving around exploring? Grazing shrimp are eating biofilm constantly - they're not starving.
- 2
Check overall health indicators
Are shrimp active, good color, moving normally? If yes, not eating prepared food is not a concern. Healthy shrimp in established tanks often prefer biofilm.
- 3
Review feeding schedule
How often are you feeding? In established tanks with biofilm, 2-3 feedings per week is often sufficient. Daily feeding may mean they're never hungry.
- 4
Reduce feeding and wait
Skip feeding for 2-3 days, then try offering food. Hungry shrimp will eat. If they still ignore food but are grazing biofilm, they simply prefer natural food.
Option 2: If Shrimp Are Truly Not Eating Anything
- 1
Test water parameters immediately
Test ammonia, nitrite, nitrate, pH, TDS, GH. Water quality issues cause appetite loss. Address any problems found.
- 2
Assess tank environment
Any new additions? Changes in lighting? Temperature shifts? Identify potential stressors that might suppress appetite.
- 3
Try highly palatable foods
Offer irresistible foods: blanched zucchini, blanched spinach, Bacter AE, or crushed high-quality pellets. Most shrimp respond to at least one.
- 4
Do small water change with matched parameters
A 10% water change with carefully matched parameters can stimulate activity and appetite. Don't do large changes.
- 5
Observe for other symptoms
If shrimp remain inactive and not eating anything (including biofilm), watch for developing symptoms. Quarantine visibly sick individuals.
Recommended Products
These are informational recommendations only. Not affiliated with any brands.
Prevention Tips
Follow these practices to help prevent this problem from occurring in the future.
- Don't overfeed - 2-3 prepared food feedings per week is sufficient for established tanks
- Remove uneaten food after 2-3 hours to prevent water quality issues
- Maintain a mature tank with natural biofilm - this is their primary food source
- Vary the diet - try different foods to find what your colony prefers
- Observe grazing behavior - shrimp picking at surfaces ARE eating
- Remember that not eating prepared food while grazing biofilm is normal and healthy
- Don't panic if new shrimp don't eat for the first week - they're acclimating
Track These Parameters with ShrimpKeeper
Get alerts when your parameters drift out of range, see historical trends, and catch problems before they become emergencies.
Download FreeOne of the most common concerns from new shrimp keepers is that their shrimp 'aren't eating.' In most cases, this reflects a misunderstanding of shrimp feeding behavior rather than an actual problem. Shrimp are continuous grazers, not meal feeders. In nature and in aquariums, they spend most of their time picking at surfaces - eating the biofilm (bacteria, algae, microorganisms) that coats everything. This constant grazing is their primary nutrition source. The prepared foods we offer are supplemental, not essential, in established tanks. An established tank (3+ months old) develops robust biofilm on glass, substrate, plants, wood, and rocks. This biofilm provides complete nutrition for shrimp. Many successful colonies thrive with minimal prepared feeding because biofilm provides everything they need. So when is not eating actually concerning? 1. **New tank syndrome**: If your tank is new (under 2-3 months) AND shrimp aren't eating prepared food, they may actually be hungry because biofilm hasn't developed. Feed more regularly until tank matures. 2. **Combined with other symptoms**: Not eating PLUS hiding, lethargy, color loss, or unusual behavior suggests a real problem - usually water quality. 3. **Sudden change**: If shrimp previously ate enthusiastically and suddenly stop, something changed. Investigate water parameters and recent tank changes. 4. **Not grazing either**: Healthy shrimp are always picking at surfaces. If they're completely still and not grazing OR eating, something is wrong. Food preferences vary between individual shrimp and colonies. Some prefer vegetables, others protein foods. Some ignore commercial pellets but devour blanched zucchini. Experiment to find what your colony likes. The most common 'problem' is actually overfeeding. Keepers offer food daily, shrimp eat when hungry and ignore when full, and keepers worry. The solution is feeding less frequently and observing whether shrimp are actively grazing - if they are, they're well-fed regardless of whether they touch the prepared food.
Frequently Asked Questions
Yes, in established tanks this is completely normal. Shrimp spend most of their time grazing on biofilm - the bacteria and microorganisms coating all surfaces. If they're actively picking at glass, plants, and substrate, they're eating constantly. Prepared food is supplemental; many healthy colonies thrive on biofilm with minimal added food.
In established tanks (3+ months with good biofilm), 2-3 times per week is sufficient. New tanks may need daily feeding until biofilm develops. If food is regularly left uneaten, you're feeding too much. Shrimp can go a week without prepared food if biofilm is available.
New shrimp often don't eat for several days to a week while acclimating. Shipping stress suppresses appetite. As long as they're exploring and beginning to graze on surfaces, they're fine. Leave small amounts of food available and give them time to settle. They'll eat when ready.
Preferences vary, but popular foods include: blanched zucchini, blanched spinach, snowflake food, Bacter AE, and quality pellets like Shrimp King. Try different options to find what your colony prefers. Some shrimp prefer vegetables, others prefer protein-based foods.
No - remove uneaten food after 2-3 hours. Decomposing food fouls water and can cause ammonia spikes. If food is consistently uneaten, feed smaller amounts or less frequently. Water quality is more important than ensuring every feeding is consumed.
Hungry shrimp swarm food within minutes of it hitting the water. If food sits untouched for hours, they're not hungry. Observe grazing behavior - shrimp constantly picking at surfaces are well-fed from biofilm. True hunger shows as reduced activity and searching behavior.
Worry if: 1) Shrimp aren't eating AND are hiding/inactive, 2) They stopped eating prepared food AND stopped grazing surfaces, 3) Not eating is accompanied by color changes, lethargy, or other symptoms, 4) It's a new tank with minimal biofilm. These suggest actual problems rather than normal behavior.
Track Your Parameters with ShrimpKeeper
Most shrimp problems stem from parameter issues. Track your water quality, get alerts when things drift, and prevent problems before they happen.