Guppies are usually confident, visible fish, so when they hide all day it feels wrong. Sometimes it’s completely normal — especially with new arrivals, a freshly rescaped tank, or after a stressful event like a temperature swing. But persistent hiding can also be a warning sign of water irritation, bullying, or a tank environment that feels unsafe. The best approach is to separate “temporary settling behaviour” from “chronic stress behaviour” and respond accordingly.
Normal reasons guppies hide
- new tank / new fish: settling takes time; lights and activity levels matter
- recent change: rescapes, loud rooms, or new tank mates can spook them
- strong lighting: bright lights with no cover can push fish into corners
Reasons hiding can be a problem
- water irritation: ammonia/nitrite, or unstable parameters
- bullying: fish hide to avoid chasing
- low oxygen: guppies may cluster oddly or stay still to conserve energy
Quick checks
- test ammonia and nitrite (must be 0)
- observe for chasing or fin nipping
- confirm temperature stability
- reduce light intensity / add a small cover zone
Short-term hiding is often just settling. But if your fish hide constantly and don’t come out to feed confidently, treat it as a signal: something about the environment isn’t comfortable. Fix stability and social layout first, and most hiding problems resolve.
