Ok, I don't have a solution for you just yet but there are a few things raising eyebrows. I usually see patchwork tissue loss when the nutrients are very low, especially with very low phosphate. That 0 ppm reading suggests that might be the case but I find it strange that you are getting this when you haven't changed the media recently. It's usually the drop that sets them off; however, if you've had extremely low phosphate for a while you could have been keeping them on a knife's edge and something tipped them over the edge.

The other is the doser. The timing of putting the doser online and the recession is suspicious. What's your dosing schedule like? How much of each are you adding at each interval and how frequently are you dosing? It might be causing fluctuations, especially in your pH. What were you doing for calc/alk maintenance before the doser?

http://a4.sphotos.ak.fbcdn.net/hphot...08312627_n.jpg

This is the underside before the flow took more off.. looks much worse now

I am dosing 3 times ago day for each. Very small amounts. I did start out 2 times each per day but up'd it a could weeks ago to keep everything at the proper levels.

Should I stop the doser when I get home and see how the tank does a week in? I also was about to change the ROWA but seen this and have not touched it yet. This latest picture is among the worst.. I was just going to frag the top and see what happens.. :(


Before the doser I was doing by hand. 10-20ml every few days of Alk and Ca, less Mg

I also dose Iron from Kent Marine Lugol's Solution Additive. I will do 1 or 2 drops every other week. Last week I might have put 3 drops in.. Not sure how that would effect it though..

Have also been hand dosing Mg. About 30ml every few days to bring it up to 1300+

Try fragging but if the colony is receding like that I wouldn't hold out much hope for the frags. Pray to the Fish Gods for mercy.

I can't see what the doser would be doing then as it would be more stable than doing it by hand (smaller doses more frequently). I'd be afraid to take it off line and have the levels start fluctuating. Go through and check your chemicals just to rule the doser out.

Lugol's is a mixture of potassium iodide and iodine, no iron in there. 3 drops shouldn't cause havoc. What size tank?

This is why I was suggesting taking a look at your snails or brittle stars. Magnesium sulphate is a muscle relaxant for some inverts, particularly snails (they actually use it to sedate snails for dissection). It MAY have an effect on SPS, I can't say. I've never heard of mag sulphate causing SPS issues like yours but it could be a possibility. If your snails or brittle stars seem to be acting funny, then this may be the culprit. They'll seem lazy, stay in the same place for long periods of time (days) and, in more extreme cases, may be unable to hold onto the rocks or glass with their foot. I dose a mixture of mag chloride and mag sulphate to avoid this.

andrew didnt you up your mg schedule lately when you got more, thats a lot of mg in volume to add to maintain, if its MgCl and not MgCl/MgSO4 then i think the clorides can elevate if im not wrong perhaps slow down on Mg dosing and do some water changes.
(I dose about 10ml/day Mg for my 180 MgCL/MgSO4 5:3) so your amount is pretty high for your volume, i know its been to raise levels but just wonder about the indirect effect of the Cl. Any one know more on this. (although I have had high Mg levels before (1500) and no ill effects ). some guys raise it to rid algae.

Sounds like a good idea Brent. I am going to go slow on the dosing and do a couple big water changes.. I hope I can save some of the coral.. It was getting big :(

My tri color acro looked exactly like that when I noticed my angelfish nipping at it. It was white I'm patches under its branches and on the base, gave it away yesterday.

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Came home late and the whole coral was white. Just removed it out of the tank. Hope it does not spread :(