So what is it? How do we get it? How do we stop it? How do we prevent it from happening again? These are all questions that need to be answered for us to be able to attack this problem rationally.

Throughout my years of SPS nurture, I have witnessed many accounts of STN that do result in some positive and much negative outcomes. There are those instances where things improve without notice, and sometimes, never even give a coral a chance to survive. The coral’s ‘skin’ recession begins at the base, and ends with the axial corallites (tips). So what is it really that makes the coral recede without warning? For now, the reasons are still ambiguous as there are many factors to consider. Some people claim that they see it begin with alkalinity swings. Some say that with temperature swings, you can get the same results. Currently, there is a new belief that in a low nutrient system (such as a Zeo, Ultralith), you can trigger an STN event. On that more later in part 2.

Here are some pictures of corals experiencing STN. Please note, these pictures are not for those of faint hearts:

While many accounts of STN can be attributed to rapid temperature fluctuations, or even alkalinity swings, none can be more perplexing as some witnessed in an ULN System (Ultra-Low Nutrient System). Stay tuned in tomorrow for my explanation on why ULN Systems are not good for your reef and what you can do to combat it.