Whatever the fish store told you about the trigger is false. There is no peaceful trigger except for those in the genus Xanthichtys and even they can be aggressive. If a trigger doesn't have enough territory and too many space invaders they become VERY aggressive. The thing that draws me to them is they are very unpredictable. A trigger can be 100 percent amiable in a tank for months then over night kill every single fish and be a trigger only tank come morning. Just warning you now. Live foods increases triggers aggression by 50 percent because they find the small fish to be a game and soon they realize all their tankmates are games. Triggers are a lot smarter than most people give them credit for. They are called the saltwater fish that is most like a dog for a reason. They are extremely intelligent. As for feeding live freshwater fish to saltwater fish it is extremely bad and will dramatically reduce a fishes lifespan. If you feed a fw fish to sw fish the fw fish has 20 percent HIGHER fat concentration than your average saltwater fish which leads to fatty liver disease which causes the liver to grossly expand and crush all surrounding vital organs. A very slow painful death. It is the equivalent of making a person eat at McDonalds the rest of their lives. It is not good and dramatically decreases the life span. Food does not raise nitrites. Food is ingested by fish which then create waste (ammonia) and that is turned into Nitrite (by nitrifying bacteria) and is then turned into Nitrate. If you do not have enough bacteria to support the bioload and their eating habits then that creates an ammonia spike which is then turned into a Nitrite spike. So you are experiencing the second part of the cycle. I would highly suggest returning a couple of the fish until you learn the ropes of saltwater. BTW, anemones don't always show problems right away. The high Nitrite will kill it within a short while. Just warning you. Anyway, good luck.
