My boss and I just started a saltwater aquarium. We bought live rock and set up the tank. A week later we bought 4 green chromis. 2 days later, one of our fish was missing his tail and the end was red and bloody. We called the aquarum store when got 2 of the fish and the live rock from and they suggested it was a mantis shrimp. The fish died. The next day another fish had a large verticle laceration on his body which progressively got worse, and it later died. We came in at night to watch for this shrimp. We found one and killed it. We then soaked all of the live rock in carbonated water for 30 minutes and found another one. We sifted through all of the live pucca shells and found nothing so we assumed we had gotten them all. We replaced the 2 fish that had died and a day later one of the fish that we replaced has a laceration like the second fish. Does anyone have any suggestions about how we can catch these and if you think there are more. Could they be anything else? The PH is 8, ammonia mostly undetectable, nitrites are less than .25, and nitrates at 10ppm. We have a 30 gallon tank. Any help would be much appreciated
