Some suggestions..i feel that you should change your return pump as some reefers mention. The flowrate is sufficient for your tank but the pump is not as reliable as Eheim pumps. i'm not saying that atman is lousy. Its just that a return pump is a very critical piece of equipment. Imagine you just spent thousands of dollars on a reef tank. You realise one day after work that your whole tank crashed because your return pump fail. Doesn't it sound logical that one should invest a little bit more just to protect your livestock? I believe that why many reefers spend a whooping 500 buck for a iwaki pump.
150w are not enough for SPS. Most tanks i have seen with 150w Mh only manage to colour some part if not none of the SPS. One Mh, like some reefers mentioned, have dark areas at the side. Which may or may not be good depending on your tank inhibitants. eg. mushrooms no need as much light. Some deeper sea fishes prefer to have subdue lightings too.
Better if can upgrade to a 400w or 2x250wMh. T5 is also a very good option. You will need to read up more to decide for yourself what is best for your system.
Just my 2 cents...