SPS Dying?

[maxxin69]

Recently I have been having the problem of my SPS (most of them at least) either dying, receding, bleaching, or going pale. All of my parameters have been the same (alk at 7.3, calcium 400 and mag 1360, PO4 between .02 and .07 and NO3 at about 5). I also haven't changed my lighting, lighting schedule, or any equipment. I have not found any sort of pests (at least the more common ones like AEFW and red bugs). Some of my acroporas are bleaching from the base and others are bleaching from the tips, but not from both at the same time. My montis are turning pale or just plain dying. LPS seem to be fine and other corals are doing better than others. I have been doing water changes but I don't see any improvement but I was thinking about running carbon.

The only change that I can think of that might have caused this would have been raising my mag up 90 points over the course of 3 days. I doubt that this would be the case, but I'm not too sure at this point. I did use ESV to raise this, so it may be a trace element(s) but I couldn't find anything on the web saying that they did include trace elements in their magnesium product.

Does anyone have any ideas why this may be, or what I can do to help them out? I am about to buy a triton test kit and see if it is a trace element.

 

[maxxin69]

Oh yeah this is only a recent problem, the tank has been set up for almost a year but this problem has only persisted a month or so.

 

[ycnibrc]

if you get a triton test look at Potassium K level if it's low then montipora is not happy. Sea level is around 400