6 bulb with good reflector is perfectly fine to grow anything in an SPS tank. But height and width should be considered. I have acros from middle to top (top being 12"+ distance between the light and the location of the coral) and montis from low to top and things color up and grow just fine. But I believe the water parameter and the aquascaping also plays their fair share of role. Ofcourse in case of T5s, the more the better. But 6 bulb is perfectly fine as long as your width and height is within 20". But since yours is 24", I would say go for 8 bulbs ATI.
__________________
You wouldn't want to see my tank. I don't use fancy equipment and I am a noob 
|