All this is highly unscientific and one dude's opinion, but more importantly in this instance I do not think your change of light fixtures or bulbs has anything to do with your troubles.
Thanks, Joe!
More and more I am leaning towards this opinion as well, that it's a biological issue and not lighting. The vinegar dosing may have been a coincidence, but either way something is not right with the water and the frag tank seems to confirm that. I'm really kicking myself for starting the vinegar dosing at that time! :headwally:
I already changed the carbon Saturday, but will do it again this coming weekend.
GFO I've had issues with in the past so i just turned it off, especially since the tank exhibits zero signs of nuisance algae at this point, except for a little in my fuge.
Those are interesting thoughts about the Cyano.
I had fought it for at least a month, trying to get it out of the tank with manually but finally had to do the lights out. I didn't want to use chemicals for the exact reason of causing problems like I'm now experiencing!
As of last night, no coral seem to be dying... no tissue loss, no stn/rtn... just not looking good.... poor color and PE. Except for a couple heads on my large frogspawn colony. So far that hasn't spread but I'm keeping an eye on it. And some things look as good as ever like the couple chalices i have, some of the montipora, my Scripps Stag, a few other sps...
Randy, I have a couple more questions for you.
Something else I noticed is that my ORP has dropped to just under 200. I run ozone for a few hours after lights on every day. It was higher than 200 last night but dropped much more after the 50g water change. Does running an ozone generator have any effect one way or the other when dosing vinegar?
And second, you mentioned earlier that the chart I was following seemed wonky. What would you have suggested as a starting point for my tank? 200g display with another 150g in sump/fuge/frag tank.