While I do that, you can continue reading about STN and the real issues. I just hope you are not reading this without our part 1, as it will be confusing! Please catch up..

Slow Tissue Necrosis is something that all of SPS coral keepers do not want to encounter. Why? Because the cause is hard to decipher. It is only through your own analysis that you can catch the catalyst for this unfortunate event. And sometimes even that is not enough.

Case in point, the Ultra Low Nutrient Systems. They are designed to purify the water that your corals are grown in. But it is through additives, such as Amino Acids/ Proteins, Vitamins, Minerals that you get them to grow and display in pastel colors. Many hobbyists in Europe and now in USA employ this kind of method through the use of a Zeo or Ultralith product system. These systems require you to perform a daily routine in adding these supplements (which I mentioned before). In reality, this is a well executed marketing campaign that people bought into. You are fabricating an environment in which you are eliminating the necessary elements that your corals use to grow (such as Phosphates and Nitrates). Then you are required to purchase supplements to make them grow and color up. Finally, and this is the kicker (if you already didn’t know), you do have to maintain a regular water change schedule. How ironic?!

Your corals are basically walking the tightrope. Why? Consider this, and this is how this ties into STN, your corals are already deprived of everything that they need to grow on. If you miss adding your supplements, or if you overdose your supplements, you will be entering in the danger zone of possibly jump-starting a massive STN event. As well, the non-marketed ULNS, such as the Vodka/Sugar/Vitamin C  (Basic Carbon Sources) are also STN event creating sources. They allow your system to eliminate the Phosphates and Nitrates from your system, but through total elimination of these important elements that your corals will go into recession.

While doing some research on STN, I found this very intersting article that depicts what I have been talking about so far. It explains how food deprivation (such as in this case through PO4 and NO3), can cause coral death. Here is an excerpt:

There is good reason to suspect that the low lipid reserves and lowered immunity features precede the bleaching event rather than result from it, as one might suspect. Widespread outbreaks of infectious diseases and parasitic problems among (not bleached) corals have been another cause of serious concern to reef scientists, also starting only in recent years. And, as mentioned earlier, slowed growth of (not bleached) corals has actually been occurring in some “pristine” areas for decades. Therefore it is reasonable to suspect that some underlying factor has caused these changes and thereby weakened coral communities as a whole, and predisposed many corals now to “bleaching” under temperature stress. Food-deprivation is certainly consistent with the pattern of presenting symptoms (slowed growth, low lipid reserves, lowered immunity and reproduction, ultimate death).

 

In other words, no food for corals, no growth for corals and their untimely death.

Tomorrow, I will show you all what you can do to eliminate the possibilities of this event. So stay tuned!

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.