i actually had a one liter bottle and cut the bottle about 1/3 of the way down so i had 2 pieces. then i cut the top big enough so he could swim in the hole. next i turn the top around and stuck it into the bottom half(making a trap that in'nt working well). i then bait it, and wait! and wait, and wait. he emptys the trap when i'm gone and he finds his way outevery time. i'm stumped cause he stays in the rocks, and won't come out to feed when i'm there. i starved him for a while, but he eats anything in the tank