Caring for a tiger moray eel (Gymnothorax favagineus) requires specific conditions to ensure its health and well-being. Here are key factors to consider:
 
1. Tank Size:
 
    •    A minimum of 75 to 100 gallons is recommended for a single adult eel.
    •    These eels grow quite large, up to 5 feet in length, so ample space is necessary to accommodate their size and swimming needs.
 
2. Water Conditions:
 
    •    Temperature: 74-80°F (23-27°C).
    •    Salinity: Needs to be in a marine aquarium with a specific gravity of 1.020-1.025.
    •    pH: 8.1-8.4.
    •    Ammonia, Nitrite, and Nitrate: Must be kept at 0 ppm for ammonia and nitrite, while nitrate should stay below 20 ppm.
    •    Filtration: A high-quality filtration system is crucial to maintain water quality, as moray eels produce a lot of waste.
 
3. Tank Setup:
 
    •    Live Rock: Provides hiding spots and mimics the eel’s natural environment. They will likely burrow or hide in crevices.
    •    Substrate: Fine sand or crushed coral is best, as it provides a natural habitat and allows the eel to burrow.
    •    Lighting: Moderate lighting, as moray eels are not particularly active during the day but prefer dimmer environments.
 
4. Diet:
 
    •    Moray eels are carnivorous, feeding mainly on meaty foods such as fish, squid, shrimp, and occasionally, shellfish.
    •    Feed them 2-3 times a week, ensuring the food is appropriately sized for their mouth.
    •    Some may accept frozen food, but offering a varied diet is key to their health.
 
5. Tankmates:
 
    •    Caution with Tankmates: Tiger moray eels are predatory and can be aggressive toward smaller fish or invertebrates. Avoid housing them with small, slow-moving fish.
    •    Compatible Tankmates: Larger, fast-swimming fish like groupers or tangs are usually a good match.
 
6. Handling:
 
    •    Avoid handling the eel directly, as they can be stressed easily. It’s best to use tongs or a net if necessary for cleaning or maintenance.
 
7. Health and Behavior:
 
    •    Tiger moray eels are generally shy and nocturnal, often staying hidden during the day and becoming more active at night.
    •    Watch for signs of skin lesions, lethargy, or reduced appetite, which may indicate stress, illness, or improper tank conditions.
 
8. Regular Maintenance:
 
    •    Perform regular water changes (about 10-20% per week) to maintain optimal water quality.
    •    Monitor water parameters frequently, especially the salinity and pH levels.
 
By providing the right tank size, water conditions, and diet, a tiger moray eel can thrive in a well-maintained marine aquarium.