I have a 125g tank,ammonia,nitrates,nitrites are at 0.salinity is 1.024,alkalinity is between 180-300,temp is 79.tank has been running for 5 months.My problem is i have two small clowns,shrimp,clams that have been in tank for two months and are doing fine but when i add new fish they die within a few days i check water parameters and they are fine earlier this week i lost a flame angle blue tang and couple of gobies but the other fish are fine.thanks for any help.