Fin nipping is one of the fastest ways to ruin a guppy display. It stresses fish, dulls colour, and can lead to secondary fin damage if water isn’t pristine. The key is understanding that nipping is rarely random — it’s usually driven by competition, boredom, or poor tank matchups.
Why fin nipping happens
- Bad tank mates: some species (and some individuals) are natural nippers.
- Line-of-sight chasing: open tanks make it easy to pursue and peck fins repeatedly.
- Food competition: when food hits one corner, dominant fish guard it.
- Overcrowding: constant contact increases friction.
Tank mates that usually behave
Peaceful bottom dwellers like dwarf corydoras and calm schooling fish like small rasboras are often safer choices. Shrimp and snails can also work as clean-up crew, but shrimp need cover to retreat.
Layout fixes that reduce chasing
- Add cover (plants/hardscape) to break line of sight.
- Create zones: a clear swim lane + a dense retreat corner.
- Soften flow: strong current tires guppies and makes them easier targets.
Feeding strategy to reduce aggression
- scatter-feed so food spreads across the surface
- feed smaller portions more often
- use sinking foods for bottom dwellers so guppies don’t guard one area
When to remove a bully
If one fish is consistently the aggressor, isolate it for a few days and watch the tank. If everyone relaxes, you’ve found the driver. Sometimes rehoming one persistent nipper is the cleanest solution.
Once nipping stops, clean water usually allows fins to recover. Keep ammonia and nitrite at 0, maintain consistent water changes, and you’ll often see fin edges regrow over time.
