<a href=showthread.php?s=&postid=9511167#post9511167 target=_blank>Originally posted</a> by ATJ
Please let me know the dimensions of the tank. This has more of a bearing on how effective the lighting is than the volume.
I do not use watts per gallon nor see any value in it. What is more important is the amount of light reaching the corals and as tanks come in all shapes and sizes, the volume of the tank does not really give a good idea how much light the corals are receiving.
I also don't subscribe to the idea that Acropora need massive amounts of light. There are over a hundred species and while some are common in shallow water, there are found over a great range of depths in nature. I have dived to over 40m (around 130') and not only are their Acropora colonies at that depth, I could see colonies in even deeper water. Of course, some species do better with more light and you will generally get faster growth with more light (with all other factors being ideal).
With the amount of light you already have you may already have enough for many Acropora species, depending on the dimensions of the tank.