Greetings All !
Quote:
Originally posted by ironman2
... most days I kinda wish the tank had just crashed and there was an obvious reason.
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Gods of the Reef ... been there, done that. Welcome to the club ...
Stay strong. The Reefkeeping Gods reward the persistent, and punish the weak ... and the
trendy.
It has been ever thus ...
Quote:
Originally posted by ironman2
I know it is low, but I hear of alot of people with LPS tanks that run there ALK low. I just have a hard time seeing the ALK or calcium causing this result unless it is extremely low. ...
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I hear what you're saying, but consider this: alkalinity is intimately tied to growth rates in scleractinian corals. Your statement, "I had very little new growth with my SPS, and slow growth with my LPS", goes right to the heart of it ...
and is suggestive that both water chemistry, and nutritional variables are in play. Whether or not alkalinity is the causal variable in the current issue or not, the corals you're working with will all appreciate a higher, stable alkalinity.
Quote:
Originally posted by ironman2
Also Most if not all of the dead and dieing corals were started as frags in this same low ALK and calcium, and have grown to large colonies. I hope that the problem is just a issue with me not dosing enough stuff. Is it possible that the corals have grown so much that they can no longer survive with the low levels?
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I caught the drift of this in your other posts, and I must say this has me a little worried that I'm missing something. I want to say ... yes, you finally reached a scleractinan density beyond which the prevailing low alkalinity and calcium levels were unable to support ... but it's too soon for that. I also would have predicted that the dysfunction would have occured much sooner than it did, and I would have told you that you would never get to the large colonies described.
So much for having a definitive model that explains things ...
Quote:
Originally posted by ironman2
... or is it possible that I have overloaded the tank with LPS and am starving them somehow?
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I
want to go here ... but don't have the evidence to back it up. Even so, two thoughts immediately stumble through my twisted little mind, with the key observation (... remembering that maybe this is wrong ...) being the outward to inward, slow creeping recession followed by necrosis.
Coral Energy Budget ... Scleractinians utilize some fascinating nutritional pathways, and they can alter the equilibrium between these different pathways in response to the conditions in which they find themselves. Whenever I see slow, creeping recession I think of both water chemistry,
and what the specimen is doing in terms of balancing autotrophy (photosynthesis), and heterotrophy (feeding). Yes ... although they are two different mechanisms, it is possible that a shut-down of skeletogenesis (CaCO3 skeleton building) due to low alkalinity/calcium could have negatively disrupted how the specimen manipulated its energy budget ... leading to slow death. Slow "starvation"? ... perhaps.
(As an aside ... you posted in the other threads that you're actively feeding the corals, yes? What are you feeding, and have you altered the feeding patterns recently?)
Tissue ... What does the tissue of the impacted specimens "look like" as the specimens progress towards necrosis? One of the more interesting ... although disturbingly ill-defined ... observations to come out of the bacterioplankton filtration camp involves the appearance of coral tissues as a health diagnostic (... not that this hasn't been commented on for a long time). Terms like "dry", "puffy", "dull", "skinny" ... and the ever so useful "good" & "bad" ...
describing the external appearnace of scleractinian tissues are being used when evaluating system status, coral health, and perhaps most relevant to this discussion ...
coral nutritional status.
At the risk of adding another variable where none is required, and of introducing a concept that is currently too ill-defined to be helpful ... have you observed any "shift" in your specimens' tissue "appearance"?
JMO ... HTH
