Fluval Hang-On Breeding Box - 16.5 x 12.5 x 12 cm (6.5 in L x 5 in W x 4.75 in H)

Honestly the best ever breeding box i have ever purchased space savings hangs on the outside once connected to air supply fills itself. No instructions needed self explanatory up and running in 5 minutes Recommend purchase will be buying another

Mounted this on a 120L community tank to isolate fry and a stressed guppy—worked spot-on. It hangs externally, so it doesn’t take up space inside the tank. Water circulates from the main tank using an air pump (not included), keeping temperature and chemistry consistent. No heater needed, no separate filtration—just plug in and go. Setup took about 10 minutes. Suction cups and brackets hold firm, even when full. Flow’s gentle—no risk of fry getting tossed around. I’ve used it for guppy fry, shrimp, and even a short quarantine stint. Easy to observe, feed, and clean. 📦 Features & Specs Capacity: 1.1 litres Mounting: Hang-on design with secure brackets Flow System: Air-lift driven—uses tank water for circulation Compartments: Optional dividers for multiple fry or isolation zones Material: Clear acrylic—easy viewing, solid build Extras: Includes tubing and flow adjuster (air pump not included) 🧪 Performance Water Quality: Stays stable—no separate heater or filter needed Noise Level: Near silent—just a soft bubbling from the air pump Cleaning: Easy to rinse and wipe down—no awkward corners Visibility: Clear sides make it easy to monitor fry or isolated fish 👍 Pros ✅ External mount—saves tank space ✅ Gentle flow—safe for fry and shrimp ✅ Stable conditions—uses tank water ✅ Easy setup—no tools needed ✅ Optional dividers—customise layout 👎 Cons ❌ Air pump not included—must buy separately ❌ Limited size—best for small fish or fry ❌ Needs level tank edge—check fit before mounting ❌ No lid—watch for jumpers or evaporation 🧭 Personal Verdict If you’re breeding, isolating, or just want a clean way to manage fry without stressing your main tank, this box is a tidy bit of kit. I’ve used it for guppies and shrimp—no drama, no losses. It’s earned its spot in the gear stash.

Quite possibly the best thing I’ve ever purchased in terms of exceeding expectation. Sturdy, well-designed, functional… I wish I’d bought this before wasting money on DIY efforts and nets. Babies are safe and secure, it’s easy to gaze lovingly at them, there are no fears about parameters… there is nothing not to love about this.

I'm currently using this to hatch and hold cory fry until they're ready to go into the main tank. By following the instructions it can be a little noisy for having it in a bedroom like I have but there's a very easy fix to that. Shorten the intake extension by pushing it up as far as you can and remove the discharge cap - it's basically silent after that and the water flows a little better. I also put a small air stone into it to provide a bit more oxygen and to make sure the entire box has warm water flowing through it. If you're looking for a silent air stone for it then I am currently using the boxtech Nano Air Stone (Y35) - it's a great combo for this box! Put in a little bit of sand, added a hide and some moss balls and it's a great box to raise fry in! Would definitely recommend with these quick fixes!

Excellent piece of kit for the aquatic breeder.

Returned but product was very good. Didn't realise it sat on the outside of tank plus your tank glass needs to be more than 5mm thick which mine is not.

Excellent, worked well but you need a separate air pump to work, as it circulates water into the small tank sitting outside of the main tank and then back into the main tank.

Attached a tiny water pump running on 3 volts to the end of the air-bubbler tube, so pumping water directly from the tank into it. This is virtually silent, as opposed to air pumps which can be quite noisy. Has been working well for a few months as our baby Platys get big enough to put back in the main tank. Ironically, since I set this up, our tank inhabitants have developed a taste for Platy fry, so I hardly ever see them before theyre eaten! Incidentally, Im not sure Id want to put a pregnant adult the size of a Platy in this for too long - its quite small if you include the separator plastics.