Coke Bottle TRap

sunken ship

I have a couple of Domino Damsels that i want to get out of my tank and I am going to try using the coke bottle trap I've heard you guys talking about. Should I place the bottle vertically or horizontally for best results?

tahoe ocean

it only took my greedy bi-color pseudochromis about 1 hour to figure out how to get in and get to the food. I had him out before any other fish could get in or he out.
But I have heard that this sometimes takes days for smarter, less greedy fish.
Good luck!:D