Can Molly live with Royal Pleco?
Caution — with care
Why
- Only a narrow water hardness overlap — keep both around 12 dGH.
- Large size gap (Molly 4" vs Royal Pleco 17") — the bigger fish may eat the smaller one as they grow.
Sweet spot: both do well at 73–82°F and pH 7–7.5 — aim there.
Side-by-side
| Molly | Royal Pleco | |
|---|---|---|
| Temperature | 72–82°F | 73–82°F |
| pH | 7–8.5 | 6.5–7.5 |
| Hardness (GH) | 12–30 dGH | 4–12 dGH |
| Adult size | 4" | 17" |
| Temperament | Peaceful | Peaceful |
| Min tank | 30 gal | 120 gal |
Together, plan on at least 120 gallons.
How to make it work
- Target the overlapping water-parameter range and acclimate slowly.
- Add only full-grown adults — never juveniles, which will be eaten.
Sort it with: GH remineraliser → Aquarium Co-Op
Where to buy
- Molly: buy at Flip Aquatics · Flip Aquatics live-arrival guarantee
- Royal Pleco: buy at Flip Aquatics · Flip Aquatics live-arrival guarantee
Live-animal shipping: add a heat pack below 50°F, expect weather holds above 90°F, and schedule delivery for a moderate week when someone can receive it promptly.
Build a full tank around this stocking →Everything compatible with Molly · …with Royal Pleco