re aquascaping
 

i have a standard 120 4x2x2 with an aquatic life 6 bulb t5 fixture 4 ati blue plus , 1 coral plus , 1 purple plus bulbs. i want to have some sps corals at the top but without a par meter im not sure how high i would have to aquascape the rocks. any input would be appreiciated

For SPS I would personally place them starting at 6" off the sand bed given your light. Obviously you can go as high as you want beyond that. You will just have to play around with various SPS species to see how much light they need/like. In fact, I wouldn't be too surprised if there are some SPS that would do fine on your sandbed even. Again, it is sort of trial and error. Some SPS need LOTS of light, some not so much. Ideally your aquascape would have various levels to place SPS as opposed to just one level.

Also, I would personally ditch the purple bulb unless you absolutely love it. With 6 bulbs to work with I would personally want to maximize my PAR. But that's a matter of opinion more than anything else :-)