my suggestions,
u could probably change yer sand as it looks too fine and yellow,
probably get a #1 sand that cost $10 for 10kg (but in singapore)
change yer light to 10k to make the tank look more white
aquascape, look at other pples tanks or coral reefs and copy ideas.. shd try to use big rocks as the base and smaller rocks at the top. lightly stack them to give it the natural look. have lots of caves so yer fishes can swim thru
hth