balloon or red acetate (semi transparent)
Length of 3/4" PVC pipe
Two 3/4" PVC end caps (or more)
Plastic lid from a food container (butter, cream
cheese, whip cream, etc...)
Length of fishing line
Quarter inch drill bit with drill
Steps: The most important step is to discover where the bristleworms concentrate. In my experience, I've found them to be in the corners where the water flow is weaker. To discover where the best place to place your trap, you will need a red flashlight and the will to get up in the middle of the night.
To make a red flashlight, cover the lens with red acetate (hobby/craft shop). Another way is to use a simple red balloon. Cut the narrow neck of the balloon off and stretch or roll it over the lens portion of the flashlight. The tighter you stretch the balloon, the thinner the material and stronger the beam of red light.
Before going to bed, plunge the room containing your tank into total darkness. Close the curtains, hide the face of illuminated clocks, etc. After three or four hours, you can approach your tank with the red flashlight. Do not shine the beam straight into the tank. Instead shine it straight down and let the "side" of the light beam enter the tank. There will still be plenty of light to see if ... and where ... your bristleworms like to congregate.
Now that you know where the bristleworms reside, you're ready to trap them.
PREPARE THE TRAP AS FOLLOWS.
Cut the PVC pipe to desired length (six or eight inches). One of the advantages of using a PVC trap is that you can cut several lengths of pipe. You may have a tight corner or small open space where you need a trap of two inches or so. The PVC trap will easily accommodate any length you wish.
Drill a quarter inch hole in the middle of the two end caps.
Cut two circles out of the plastic lid a tad smaller that the diameter of the end caps.
Use the aquarium sealant to glue the circles to the outside of the end caps. If you have a problem getting the plastic circles to "stick" because they are too smooth, you can rough them up first with sand paper.
Be sure the sealant does not fill the quarter inch hole drilled into the end cap.
After the sealant has cured (approximately 24 hours), use a sharp knife or razor blade and cut an "X" in the plastic lid where it covers the quarter inch hole in the end cap.
Using the blunt end of the knife or a screwdriver, "bend" the four tabs of the "X" down into the inside of the end cap.
Insert the length of PVC pipe into the two end caps.
Do not glue the end caps in place, as you will need to remove the caps to empty the worms you catch.
Tie one end of a small length of fishing line around the middle of the PVC pipe, and tie a loop in the other end of the fishing line.
Now your trap is complete.
The idea of using a "plastic lid" with an "X" came from Mr. Albert Thiel. The concept is bristle worms can push their way through the four tabs of the "X" to get inside, since they are travelling in the same direction as the tabs are bent. When they try to crawl out, the tabs bend back out, thus "shutting" the opening.
As a hint, prepare several pairs of end caps. The preparation as described above will catch medium to small worms. You can catch the bigger worms by first snipping the very tip (half a millimeter) of each tab before bending it down. By having several different pairs of end caps, you can catch different sizes of worms, depending on the"size"of your bristleworm problem.
The trap is now ready to be used.
There are several kinds of baits you can use.
Different baits will have different results.
I prefer using freeze dried "Jumbo Shrimp" commonly sold in pet stores. It is easy to break into small pieces (pea size), you don't have to visit your local fish market, nor have to freeze it to keep it from spoiling. Break off three or four "pea" size pieces of bait.
Drop the bait into the PVC trap and recap it. Put the trap into your tank vertically and let it fill with water. You can then drop it in the desire spot, or use some type of hook and the loop of the fishing line to place it exactly where you want it.
Then shut your lights off as you normally do. Be sure to close curtains and turn off ANY other lights. The next morning, use a hook to "lasso" the loop of the fishing line and lift the PVC out of your tank. You may wish to use a small bucket to place the trap into, since it will leak water once removed from the tank.
Final step is to remove one of the end caps and see how successful you were the night before. There are several reasons I like the above trap over a few others I have tried. First, the PVC is denser than salt water, so it will naturally sink. You don't have to bury or weigh it down to keep it on the bottom of the tank. Second, it is easy to switch end caps to catch different size worms. The major reason, is that it is easy to place and remove from the tank using a "hook" and the loop of the fishing line. This keeps your arms out of the tank and reduces any stress on the inhabitants.