Am i too immature ?

[DEAD_BY_DAWN]

well after three months the 90g doing well,othere than a slight case of ick
i would like to start adding a few inverts that interest me ,i already have a nice sand star,but a cucumber and a queen conch are in the plans but i dont want them starving to death,there is about 100lbs of ls and 65ish pounds of lr,should i let the tank mature for another few months before adding any other inverts ?.thanks john