Ah well that wont help then, they really shouldnt be in a 30g even though they may still be small they will need a much larger tank. Even for one your looking at a minimum of a 75g, best advice would be to return them to the LFS or re-home them with someone with a larger tank. I know its not the advice you want to hear, but you have to think of the health and happiness of the fish above your own desire to keep them.