Just found SiG's piece on 'Iodine in the Reef Aquarium' and the following extract is very interesting:
'Over the last several years I and a few others have witnessed a regular phenomenon whereby previously healthy and well run tanks with seemingly perfect water conditions suddenly start to show a downturn in the health of SPS and other stony corals. The visual symptoms are pretty much standard across the board, i.e. an initial thinning of the tissue on the exposed tips and upper surfaces of the branches of Acropora's near the top of the tank. Which makes it look as though the tips have been 'nibbled' or 'bitten'. Quite often encroaching algae will immediately start growing on the tips giving rise to the common diagnosis that the algae are the problem or that there is a problem with the lamps. As things get worse this damage progresses with increasing loss of pigment, powdery tips, various degrees of tissue necrosis across exposed areas until the colonies finally collapse and die. Also affected are plating Montipora etc, which will pale off and start going soft at the growth edge. commonly the colonies will start loosing patches of tissue from the inner regions of the plates which gradually spreads out until the entire colony collapses'
Now, link that with my post in the SPS section
http://www.internati...?showtopic=4004 and why I started this thread, and it seems to follow a trend.
Where's SiG when you want him????
Help
,questions,questions
Thought I might have been on to something, but if your getting the same results, its back to the drawing board! 
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