SPS issues?..

[ScubaSteve]

Originally Posted by ashr

I was just going to frag the top and see what happens..

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.

Originally Posted by ashr

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

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.

Originally Posted by ashr

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..

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

Originally Posted by ashr

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

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.