Fish Breeder Boxes
Open top boxes with slotted walls and a slotted floor that hold small fish apart from the tank. Hang one over the rim or mount it on your own suction cups.
A breeder box holds small fish apart from the rest of the tank. Three walls and the floor are cut with slots, so water moves through the box, and the back wall stays solid against the glass. We build them with 1.5mm slots and with 3mm slots. That slot width is our own choice, not a tested number, so read the size and decide for yourself whether it suits the fish you keep. Pick the rim hang version to drop it over the tank wall, or the suction version to use your own cups.
Fry Saver Box, Nano, 1.5mm Slots, Rim Hang
An open top box with 1.5mm slots in its walls and floor that hangs over the tank wall and holds small fish apart from the tank.
Fry Saver Box, Nano, 1.5mm Slots, Suction Mount
An open top box with 1.5mm slots in its walls and floor that mounts on the glass with your own suction cups and holds small fish apart from the tank.
Fry Saver Box, Nano, 3mm Slots, Rim Hang
An open top box with 3mm slots in its walls and floor that hangs over the tank wall and holds small fish apart from the tank.
Fry Saver Box, Nano, 3mm Slots, Suction Mount
An open top box with 3mm slots in its walls and floor that mounts on the glass with your own suction cups and holds small fish apart from the tank.
Fry Saver Box, Standard, 1.5mm Slots, Rim Hang
An open top box with 1.5mm slots in its walls and floor that hangs over the tank wall and holds small fish apart from the tank.
Fry Saver Box, Standard, 1.5mm Slots, Suction Mount
An open top box with 1.5mm slots in its walls and floor that mounts on the glass with your own suction cups and holds small fish apart from the tank.
Fry Saver Box, Standard, 3mm Slots, Rim Hang
An open top box with 3mm slots in its walls and floor that hangs over the tank wall and holds small fish apart from the tank.
Fry Saver Box, Standard, 3mm Slots, Suction Mount
An open top box with 3mm slots in its walls and floor that mounts on the glass with your own suction cups and holds small fish apart from the tank.
Breeder box questions, straight answers.
Should I pick the 1.5mm slot or the 3mm slot?
Slot width is our own choice, not a tested number. The 1.5mm slot is the narrower option for the smallest fry. The 3mm slot moves more water through the box. Read both sizes and pick what suits the fish you keep.
Should I get the rim hang version or the suction version?
Pick the rim hang version to drop it over the tank wall. Pick the suction version if you want to use your own suction cups instead.
Why is one wall solid while the others are slotted?
The back wall stays solid against the glass. The other three walls and the floor are cut with slots, so water moves through the box.
Does water move through the box on its own?
Yes. The slotted walls and floor let tank water pass through without any extra pump. Water movement comes from the slots, not from an add on part.
Can I use the box for something other than newborn fry?
Some keepers use a slotted box to hold any small fish apart from the rest of the tank, not only newborn fry. Check the slot width against the fish you plan to separate.
Fish Breeder Box vs Breeder Net: Fry Saver Sizing and What the Slot Width Means
A fish breeder box holds its shape. A breeder net does not. See the real sizes, the two slot widths, and what a slot width actually tells you.
Read the guideGive small fish their own space in the tank.
Pick your slot width and mount style. Printed to order in the USA.
Need a size we do not stock? Use the custom builder.