How Breeder Boxes Work
A plastic box suspended in the main tank isolates pregnant females or newborn fry from adults.
Water flows through slits letting shared bacterial colony and temperature stabilize conditions.
Pros
No extra heater, filter, or tank footprint.
Fry stay in the main tank bacterial environment.
Easy to observe and feed.
Cons
Female stress can trigger miscarriage, premature delivery, or reabsorption of embryos.
Limited swimming space stunts fry if kept too long.
Some designs are too small and cause physical injury.
Best Practices
Only add female when visibly close to delivery (squared belly, gravid spot very dark).
Remove female within 24 hours of delivery to reduce stress.
Move fry to a dedicated grow-out tank by day 7 for proper growth.