From reeftime.
Have you ever tried to catch a particularly feisty fish in an aquarium that is heavily planted or full of delicate live rock? If the answer is yes, then read on! This article will teach you how to make an aquarium safe fish trap. This simple, but clever DIY fish trap will help you catch a delicate fish with no damage to aquarium life or the fish itself.
What you will need:
A 2-liter bottle
A tool to cut the 2-liter bottle
A bit of fish food that is highly favored by the fish you are attemping to capture
Directions
Start by cutting the top 4.5 inches off of the 2-liter bottle. If your fish is too large to fit into the screw top area, cut off the screw top off the bottle to make a large enough openeing for your fish to swim into. The red lines in the diagram to the right show where to cut.
If you needed to cut the screw top off of the bottle you can discard that portion. The top part should now form a funnel. Invert this funnel and insert it into the bottom portion of the bottle. It may be neccesary to make a cut in the bottom portion of the bottle to fit the funnel inside it.
The DIY fish trap construction is now complete.
Setting the fish trap
Place some food in the fish trap, and submerge it in your aquarium. You may have to take the funnel back out to ensure the trap gets full of water. If you need to sink the fish trap to the bottom, you can put a little aquarium gravel from the tank inside the trap. Just leave the fish trap in the aquarium until the hungry little fish you want to catch swins right in!
Here is a diagram of the completed fish trap: