Firefish Goby and Molly Compatibility Overview
Firefish Goby and Molly are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
| Factor | Firefish Goby | Molly | Verdict |
|---|---|---|---|
| Temperature | 72โ82ยฐF | 72โ82ยฐF | โ 72โ82ยฐF |
| pH Range | 8.1โ8.4 | 7.5โ8.5 | โ ๏ธ 8.1โ8.4 (narrow) |
| Temperament | peaceful | peaceful | โ Compatible |
| Adult Size | 3.0 in | 4 in | โ Similar |
| Min. Group | 1+ | 3+ | See below |
| Min. Tank Size | 55 gallons (for both species) | โ | |
Compatibility Positives
Incompatibility Reasons
Species Profiles
Firefish Goby โ Nemateleotris magnifica
The Firefish Goby is a popular choice for saltwater aquariums due to its vibrant colors and peaceful nature. These goby fish thrive in well-maintained tanks with plenty of live rock for them to explore. They are best kept in pairs or small groups and can be a great addition to a community tank with compatible species.
โ Full Firefish Goby care guide
Molly โ Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water โ sometimes slightly brackish. Prolific breeders; peaceful community fish.
Frequently Asked Questions
Can Firefish Goby live with Molly?
Generally not recommended. Firefish Goby and Molly are generally not recommended to be housed together. One of these is a marine species and the other is not; they cannot share one aquarium. Their usable pH overlap is narrow and requires stable, tested water. Review the behavior and water details before deciding whether to attempt the pairing.
What tank size do I need for Firefish Goby and Molly together?
A minimum of 55 gallons is recommended for keeping Firefish Goby and Molly together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Firefish Goby and Molly?
72โ82ยฐF โ inside Firefish Goby's 72โ82ยฐF and Molly's 72โ82ยฐF.
Is a Firefish Goby aggressive toward a Molly?
Firefish Goby is peaceful and Molly is peaceful. No major aggression issues are expected between these species.
Related Compatibility Guides
Tank Size for Firefish Goby and Molly
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 55 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 75 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 125 gal | Best when keeping larger schools or reducing territorial pressure. |