adding 4 new fish and BS light is on

[firecoral3msd]

I have had my 150g tank up and running since december of 2006. I have one clownfish in this tank, two anemones, CUC, 5 inch deep sand bed, carbon filtration, refugium full of macro algae and it has mangroves. I have just bought 4 new fish and people are telling me on a different forum. That adding 4 small (sizes 1.5"-3") fish all at once to my established tank, could cause an ammonia spike and kill all of my fish. LOL am I the only one that thinks this is complete bull?