i know triggers are not good choice for reef tanks. i have a niger and huma huma. i put them in my thanks when they were 1 1/2 inch each or less. i love them and always had triggers in my reef. they do not bother my coral. if the shrimps are in tank and settled before trigers,some times you have a good chance that they will not bother your shrimps. the only thing that annoys me is than my triggers dig in the sand a lot and then carry sand in their mouth and spit it all over my corals ,so i have to constantly use my kent scraper to move the sand from my corals. they eat everything and they love the green nori ,i put in the tank for my yellow tang. they have never hurt each other and they have never killed or hurt any other fish. when i first introduced them they killed most of my crabs and snails,but now whatever crab and snails i have and that survived they do not bother. they are like puppy dogs. they have their own cute personalities . we just know general rules on fish personalities, but fish are like humans with individual personalities. you can have 2 of the same speices fish,one can be an angel and the other a devil. give your trigger a chance to settle in ,they are good eaters . good luck. jakleen