Hello Sreeni and Welcome to R2R and the salty side of the hobby. I like what you have done with the tank so far. I do agree that you will need a larger tank for the tangs. I have a 180g with several tangs. I also have a 32 biocube that has two yellow tangs. I know that they will go into the 180g eventually. The two yellow tangs have been together since I purchased them at approximately 1 inch.