How to Make a DIY Fry Trap for Breeding Aquarium Fish

In our previous article How to Raise Baby Fish Fry in Your Aquarium, we mentioned several techniques that help prevent the adult fish from predating on their offspring. Many fish farms and breeders have significantly increased their fry survival rate by making DIY fry traps — simple enclosures with holes that are small enough for the young to swim through but not big enough to let the parents pass. You can put all the adults or a pregnant livebearer inside the trap so that the eggs and fry escape through the holes. Conversely, the parents can be placed outside the trap and the fry can swim inside for safety. Our CEO Cory and master breeder Dean have their own methods of making fry traps, so we’ve included instructions for both down below:

How to Make Cory’s DIY Fry Trap

1. Gather the materials. Most of these items can be purchased at arts and crafts stores.
   1. Acrylic yarn
   2. Rectangular sheet of plastic craft mesh (size #5 or #7)
   3. Circular sheet of plastic mesh canvas (size #5 or #7)
   4. Plastic yarn needle (that can fit through the mesh holes)
   5. Scissors
   6. 2 binder clips
   7. Gravel or rocks
2. Thread the needle by pulling the yarn through the eye of the needle for about 6 inches so the yarn won’t fall out.
3. Curl the rectangular craft mesh into a cylinder so that the edges slightly overlap and use the binder clips to keep the two ends connected.

4. Sew the two ends of the craft mesh together using a running stitch.
   1. Use the needle to insert the yarn downward into the craft mesh and pull it through the inside of the cylinder. (Make sure to pull enough yarn through so you can finish sewing the whole edge.)
   2. Push the needle upward through the next hole in the craft mesh and pull the rest of the yarn through to the outside of the cylinder.
   3. Repeat steps 4a and 4b until the entire edge is sewn together. Cut the yarn ball off and tie off the two loose ends of yarn.

5. Cut the circular mesh canvas so that it fits the bottom of the cylinder.

6. Thread the needle again with yarn and sew the circular canvas to the bottom of the cylinder using a whipstitch.
   1. Insert the needle into the bottom most edge of the cylinder and angle the needle upward so it goes through the circular base. Pull the yarn through so you have enough to finish sewing the whole edge.
   2. Insert the needle through the next hole along the bottom edge in the cylinder and then through the circular base. Pull the yarn through.
   3. Repeat step 6b until the entire bottom seam is sewn together. Cut the yarn ball off and knot the two ends of the yarn together.

7. (Optional) Make a few spawning mops without the cork and tie them to the outside and inside of the cylinder to attract the baby fish.
8. Place the cylinder in the aquarium and put gravel or rocks inside to prevent it from floating. The cylinder should be tall enough so that the top edge is out of the water and adults cannot jump over the walls.

How to Make Dean’s DIY Fry Trap

1. Gather the materials. (As an Amazon Associate, we earn from qualifying purchases, and commissions may be earned from the links below.)
   1. Polyfoam caulk saver
   2. Pond plant basket
   3. Scissors
2. Cut off the end of the caulk saver so it has a straight edge.
3. Push the caulk saver under the outside lip of the basket.

4. Cut the caulk saver to size so it fits the diameter of the basket.
5. Reinforce the caulk saver by firmly pushing it into the basket rim. It shouldn’t fall out, but if desired, you can first line the basket rim with 100% silicon sealant to adhere it permanently.
6. Place the basket in the fish tank. For a 10-gallon aquarium, the basket can rest on the tank rim. For a larger aquarium, the basket can float in the water.

DIY fry trap basket with pregnant female guppies inside

With your new fry trap, the number of fish you breed and raise should increase substantially, so consider selling the extras to your local fish store or directly to hobbyists. For more information, read our article on How to Breed Aquarium Fish for Profit.