I wouldn't use your bilge pump...it might be okay for a while in muddy areas, but sand and other grit will eventually destroy it. I'm not sure, but I think it might be a little hard on the ghost shrimp too.
Ghost shrimp slurp guns are easy to make if you have a hacksaw and die set.
You'll need:
- 3 feet of 3" pvc pipe and 3" pvc cap
- Garden sprinkler handle - the kind that are about 3 ft long
- 3" kids rubber ball
- 2 stainless steel nylock nuts and 2 fender washers that fit the sprinkler handle.
- cut the "key" end off the sprinkler handle with a hack saw.
- drill a 1/4 " hole through the center of the pvc cap. slide the cap onto the sprinkler handle.
- thread about 4" of the sprinkler handle with a die that matches the nut threads.
- thread one nylock nut on as far as it will go (4") followed by a big fender washer. you want at least 1.25" od. you may have to use 2 washers that fit and two that are a couple of sizes bigger.
- drill/poke a 1/4" hole through the center of the rubber ball.
- slide the ball onto the sprinkler handle followed by a fender washer and nylock.
- Tigten the nut so that ball squishes out enough so that there's enough suction and that it also still pulls easily enough. Overtighten and it will be too hard to pull.
- slide the ball into the pvc tube and press on the pvc cap. no need to glue - you want to be able to adjust or replace the ball later if it wears out.
If you have the tools it should cost $5-10.
Otherwise I'd buy one for $20 at Squidco. 