Compatibility Overview
Royal Gramma and Weather Loach are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
| Factor | Royal Gramma | Weather Loach | Verdict |
|---|---|---|---|
| Temperature | 73–81°F | 59–72°F | ❌ No overlap |
| pH Range | 8.0–8.5 | 6.5–7.5 | ❌ No overlap |
| Temperament | semi | aggressive | ❌ Risk |
| Adult Size | 1.6 in | 3.9 in | ⚠️ 2.4× difference |
| Min. Group | 1+ | 1+ | See below |
| Min. Tank Size | 40 gallons (for both species) | — | |
✅ Compatibility Positives
❌ Incompatibility Reasons
Species Profiles
Royal Gramma — Aquarium species
The Royal Gramma, known for its vibrant blue coloration, is a popular saltwater fish among beginners and experienced aquarists alike. It requires a well-maintained tank with plenty of swimming space and a moderate current. With a peaceful temperament and a relatively easy care routine, the Royal Gramma can be a great addition to a community tank. Its delicat
→ Full Royal Gramma care guide
Weather Loach — Aquarium species
The Weather Loach, also known as the Weather Fish, is a popular addition to freshwater aquariums due to its peaceful nature and intriguing behavior. It has a slender, eel-like body with a translucent appearance and dark spots. These loaches are active and enjoy exploring their tank, making them a moderate activity level fish. They do not school and are gener
Frequently Asked Questions
Can Royal Gramma live with Weather Loach?
Generally not recommended. Royal Gramma and Weather Loach are generally not recommended to be housed together. The issues listed above — whether water parameter incompatibility, predation risk, or aggression — create conditions where one or both fish are likely to suffer harm or chronic stress.
What tank size do I need for Royal Gramma and Weather Loach together?
A minimum of 40 gallons is recommended for keeping Royal Gramma and Weather Loach together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Royal Gramma and Weather Loach?
No overlap
Is a Royal Gramma aggressive toward a Weather Loach?
Royal Gramma is semi and Weather Loach is aggressive. These animals require different water types and cannot share one aquarium.
Related Compatibility Guides
Compatibility score breakdown
The overall score is weighted across water chemistry, behavior, adult size, swimming zone, and social needs. A score is a planning aid—not a guarantee for individual fish.
| Factor | Score |
|---|---|
| Temperature | 0/100 |
| Ph | 0/100 |
| Temperament | 25/100 |
| Adult Size | 72/100 |
| Swim Zone | 92/100 |
| Social Needs | 92/100 |
Tank size scenarios
Use the scenario that matches the actual group sizes and temperament you plan to keep.
| Scenario | Tank | When it applies |
|---|---|---|
| Minimum viable | 40 gal | Only for the recommended minimum groups, mature filtration, and close monitoring. |
| Recommended community | 55 gal | Adds territory, swimming room, and a safer buffer for behavior. |
| Low-conflict setup | 75 gal | Best when keeping larger schools or reducing territorial pressure. |