Compatibility Overview
Molly and Pea Puffer can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
| Factor | Molly | Pea Puffer | Verdict |
|---|---|---|---|
| Temperature | 72–82°F | 74–82°F | ✅ 74–82°F |
| pH Range | 7.5–8.5 | 7.0–8.0 | ⚠️ 7.5–8.0 (narrow) |
| Temperament | peaceful | semi | ⚠️ Monitor |
| Adult Size | 4 in | 1 in | ❌ 4× difference |
| Min. Group | 3+ | 1+ | See below |
| Min. Tank Size | 55 gallons (for both species) | — | |
✅ Compatibility Positives
⚠️ Caution Points
Species Profiles
Molly — Poecilia sphenops
Hardy livebearers that prefer alkaline, hard water — sometimes slightly brackish. Prolific breeders; peaceful community fish.
Pea Puffer — Carinotetraodon travancoricus
World's smallest pufferfish — intensely territorial and nippy despite tiny size. Will attack fins and eat shrimp and snails.
Frequently Asked Questions
Can Molly live with Pea Puffer?
With significant caution and a larger tank. Molly and Pea Puffer can potentially coexist, but the combination requires careful attention. Some combination of water parameter differences, size mismatch, or temperament issues make this pair challenging. A larger tank (minimum 55 gallons), dense planting, and close monitoring are essential.
What tank size do I need for Molly and Pea Puffer together?
A minimum of 55 gallons is recommended for keeping Molly and Pea Puffer together. A larger tank improves water stability and reduces territorial conflict.
What temperature suits both Molly and Pea Puffer?
74–82°F
Is a Molly aggressive toward a Pea Puffer?
Molly is peaceful and Pea Puffer is semi. Limited pH overlap (7.5–8.0) — maintain pH carefully within this narrow window.