Water chemistry is the most important aspect to keeping successful SPS corals in your reef aquarium. Stable and consistent calcium and magnesium are important, but the most critical parameter to monitor is alkalinity. A quick 'alk swing' (change of 1dkh or more in less than 24 hrs) can have a negative impact on growth, colour or even lead to other issues. SPS coral utilize some nutrients in our water, so be sure to maintain both No3 (nitrate 5-15ppm) and Po4 (phosphate .02-.08). Lower levels will lead toward SPS corals losing colour or even STN (slow tissue necrosis).
When considering flow for an SPS coral dominated or mixed reef, try to be sure that water is moving through every part of each SPS coral. Monitor movement of the coral's polyps to ensure that the coral has no dead flow areas within its branches. This becomes more of a challenge as SPS colonies grow and create intricate networks of branches. A lack of flow can inhibit an SPS coral's growth or cause detritus build up within the branches, potentially leading to STN.
SPS corals tend to be the highest light demanding of any coral. They form their structures in fairly shallow waters in the wild, receiving lots of direct sunlight every day. In our aquariums, it is important to consider a lighting or a combination of lights that gives the SPS corals a strong peak or daylight spectrum (for growth) and a deep blue spectrum (to get the colours to pop). Most SPS coral, especially acropora species, should be mounted in the higher regions of most aquariums. We use a combination or blue LED and ATI T5 on our SPS coral systems, on a 10-11 hr photoperiod, the first and last 2 hours being blue LED only.