Help me understand this.

[amuruges]

Taking an already established system with high nutrient level to nutrient starvation using zeo need to be done very slowly. The rational I understand is that, abrupt changes in nutrient reduction levels will trigger RTN on sps acros mainly. Am I wrong if so, what actually triggers RTN if rushed in on established tanks?

Now for the second part, will having nutrient starved env affect acquiring new frags/corals from a non-zeo/high nutrient systems, once you bring your system to zeo phase? If so, How do you handle this and not loose a whole bunch of new purchases. If not, why not? tks.

[Aged Salt]

Good questions TN both slow & rapid seem not to be triggered by the same process & actually both shut-downs in our corals are not well understood. You could read for days & still end-up unsure why some corals TN while others do not In theory, the ZEOvit guidelines are given to slowly reduce nutrients, allowing our corals take to adjust to the new environment, thus the cycling recommendation for the zeolite reactor--to reduce the nutrients N03's/P04's evenly & slowly. Also the reason for upgrading Start1 with Start2, which does not cause TN, even in excess. If you know well the ZEOvit guide, expertly written by Alexander ****, you will notice the various dosing differences given the nutrient state of one's aquarium. Many times, when I make recommendations, the dosages are very conservative & I try to point out to the new user, not to be impatient. But human nature is such that at times, this is difficult. Remember, SPS corals are very sensitive to changes in their water composition, nutrients being only one of the factors involved.

I have been using ZEOvit method now for nearly 2 yrs. now, & I've never noticed any TN's when adding new corals from higher nutrients to my reef. BTW, in general frags especially aquarium-generated ones, seem to adapt to water chemistry differences much better than wild colonies, which have not had to alter their energy producing sources before introduction into our tanks. Bob

[mesocosm]

Greetings All !

Taking an already established system with high nutrient level to nutrient starvation using zeo need to be done very slowly. The rational I understand is that, abrupt changes in nutrient reduction levels will trigger RTN on sps acros mainly. Am I wrong if so, what actually triggers RTN if rushed in on established tanks?...

It's been my experience that abrupt changes in any of the fundamental variables in a captive ecosystem can generate RTN in SPS specimens ... particularly among Acropora species. As Bob pointed out ... you can get lost in the variable interactions without reaching any conclusions, but ... my list of parameters/variables which are possible RTN triggers when an abrupt "shift" takes place includes NH3/NH4, PO4, pH, temperature, radiation (light), KH, and dissolved oxygen. Also on the list are physical traumas (handling & transport), allelopathy, accumulation of inorganic toxins, an absence of essential nutrient(s), and pathogens.

Not to quibble over terminology ... truly ... especially since your question was not only excellent, but straightforward ... but, I'm not at all ready to concede that the ZEOvit methodology generates a water column which could be described as "nutrient starved." Quite the contrary. The bacterial aggregates ("mulm") resulting from agitation of the biofilms formed on the ZEOvit media are very nutritious, and are easily captured by the mucus "nets" of SPS specimens ... as well as by LPS, zoanthid, and corallimorph specimens.

... Now for the second part, will having nutrient starved env affect acquiring new frags/corals from a non-zeo/high nutrient systems, once you bring your system to zeo phase? If so, How do you handle this and not loose a whole bunch of new purchases. If not, why not? tks.

Again, apologies if this comes across as nitpicky quibbling ... ...

... but the term that leaps to my mind regarding a water column with parameters in line with 0 ppm NH4, 0 ppm NO2, 0 ppm NO3, ~0.02 ppm PO4 measurements (in other words, analogous to natural seawater around reefs), is oligotrophic ("This term is usually used to describe bodies of water with very low nutrient levels" en.wikipedia.org/wiki/Oligotrophic) ... as opposed to starved ("suffering from lack of food" wordnet.princeton.edu/perl/webwn).

I risk coming across as obnoxiously redundant because the distinction is important ... not merely in terms of assessing the ZEOvit methodolgy, but more importantly in terms of the much larger question of how to best manage the needs of SPS specimens in a captive environment. A starved environment is deficit in terms of nutritional requirements (which would fall into my criteria for possible RTN generation), while an oligotrophic environment is low in terms of nutritional requirements (which limits productivity, but does not generate RTN in and of itself).

... If so, How do you handle this and not loose a whole bunch of new purchases. If not, why not?

The ZEOsystem that I ran was atypical in that it was a "working" system, i.e., it was used to acclimate SPS specimens (a a few other things) and to present them for resale in an LFS setting. The specimens were acquired two different ways: (1) directly out of the transship box; and (2) picked from 104th street wholesaler holding systems (Walt Smith/Pacific Aqua Farms, SDC, QualityMarine, and Underwater World) after having been in their holding systems for anywhere from 12 hours to ~14 days.

I never noticed any RTN that I could attribute to a "nutrient shift" by virture of being placed into the ZEOsystem. I did occassionally experience RTN that was clearly related to physical trauma and/or pathogens ...

... or placement stupidity on my part ...

BTW, in general frags especially aquarium-generated ones, seem to adapt to water chemistry differences much better than wild colonies, which have not had to alter their energy producing sources before introduction into our tanks.

Indeed. The reaction of the wild colonies to the ZEOsystem eliminated any concerns I had about "water chemistry differences."


JMO ... HTH

[amuruges]

Excellent posts guys. Thankyou I am very new to saltwater so Still learning as much as I can. BTW - I do like the term low nutrient to starved... Does make a world of difference.