Saltwater Fish Compatibility Checker

What is the Saltwater Fish Compatibility Checker?

The Saltwater Fish Compatibility Checker checks whether saltwater fish are compatible tankmates with other species. Behavior and compatibility mismatches are a common reason introductions go poorly or pets end up stressed, a little upfront assessment goes a long way.

Saltwater fish generally live 5-15 years when they are well looked after. Diet-wise they are an omnivore, which shapes almost every feeding decision you make. Marine tanks demand stable salinity, mature live rock and a slower cycle than freshwater. Most losses happen in the first six months from rushing stocking, and a quarantine tank is close to essential. Keep an eye out for marine ich (cryptocaryon), velvet, brooklynella. These are the conditions saltwater fish are most commonly seen for.

How does the Saltwater Fish Compatibility Checker work?

The result comes from a weighted set of common, well-documented behavioral factors rather than a single yes/no rule, since real compatibility and temperament are rarely black and white. It is a starting point, not a verdict. Somebody who has actually examined your saltwater fish will always know more than a formula does.

Factors that matter

• Household composition: other pets, children, and general activity level all matter
• The individual animal's history and socialization, which can outweigh general breed or species tendencies
• Living environment: including space and access to outdoors
• Your own experience level and lifestyle, which affects how well a given temperament fits

How do you use the Saltwater Fish Compatibility Checker?

1. Answer "Young children in the household?"
2. Answer "Other pets already at home?"
3. Pick your household activity level (Low, Moderate, High)
4. Pick your hours the animal would be alone each day (Under 2, 2 to 5, 5 to 9, ...)
5. Pick your your experience with this species (None, Some, Extensive)
6. Press Calculate, then read the result alongside the sources listed below

If the result looks wrong, check your inputs before you worry. Entering weight in the wrong unit is easily the most common reason a figure looks off.

For related questions, see the other behavior tools or browse every saltwater fish tool.

Before you rely on this

This calculation assumes a healthy adult saltwater fish with no complicating conditions. Pregnancy, recovery from illness, medication and significant age at either end of the scale all change what is appropriate. When in doubt, the safest move is to take the number to a vet and ask whether it fits your particular animal.