Fluval Hang-On Breeding Box Large
Designed for easy attachment to the side of most aquariums with a thickness of up to 1 inch, the Fluval Multi-Chamber Holding & Breeding Box offers up to three distinct compartments to safeguard fry, unwell or frail fish, or newcomers needing acclimation.
Highlights
- Versatile breeding box with options for 1, 2, or 3 separate sections
- Perfect as a nursery and incubator to shield newborn fry from predators, boosting their chances of survival
- Acts as a secure refuge for fish that are injured or weak
- Facilitates the acclimation of new fish by allowing water flow from the main aquarium through the box
- Conveniently hangs on the outside of the aquarium for easy monitoring and upkeep
- Compact and space-efficient design
| Feature | Detail |
|---|---|
| Number of Compartments | 1, 2, or 3 |
| Attachment Type | Hang-on to aquarium side |
| Max Aquarium Thickness Support | Up to 1 inch |
| Primary Use | Fry protection, injured fish refuge, new fish acclimation |
FAQ
Can the breeding box be used for acclimating new fish?
Yes, the box allows water flow from the main aquarium, enabling gradual acclimation of new fish.
How many compartments does the large version offer?
The large version offers up to three separate compartments.
Is the box easy to install and maintain?
Yes, it attaches securely to the side of most aquariums and can be easily monitored and cleaned from the outside.

Adrian Abraham –
This breeding box has been a game-changer for my fry. I used it to protect newborn fish from larger fish, and the survival rate improved significantly. The setup is simple and it stays securely in place. I also used it to acclimate a new fish, and it worked well without stressing the fish.
Sally Carr –
I appreciate the three-compartment option. It’s perfect for separating different stages of fish development. The water flow helps maintain stable conditions, and it’s easy to monitor daily. A little bit of adjustment is needed for positioning, but overall very effective.
Victoria Mathis –
The box is sturdy and fits well on my 20-gallon tank. I used it to keep a weak fish safe while it recovered. The design allows for natural water flow, which keeps the water quality stable. I’ve seen a noticeable improvement in the health of the fish inside.