Corals dissolving?

[txmidget]

I have several hammer and frogspawn corals. They appear healthy except that the stalks are dwindling in size and getting smaller and thinner. The heads look fine. I have had a couple get so thin that the head breaks off completely. I have checked at night for predators, although I have quite a few fireworms they dont appear to be bothering my corals much. I do see quite a few little white bumps on them, the same as the little white spots you see on the glass are these something to worry about?
A low calcium problem maybe? Condition in tank are optimal except the Calcium which is staying about 350.
Would an iodine dip be beneficial or harmful? Any suggestion would be appreciated.

[EdKruzel]

Iodine would probably kill them. The skeleton is comprised of calcium. At 350 it is "starving" or becoming weak and wasting away.
Begin to dose a calcium supplement such as B-Ionic, Aragamilk, or a Kalkwasser drip.

You should maintain a level between 400-460ppm

Ed

[Phan]

txmidget - are they growing towards the light? like....are the stalks....that are getting smaller....simply in the shade?

[txmidget]

Ed: I thought perhaps that would be the problem that they are starving for Ca, but figured that would affect the heads rather than the stalk which seems basically dead or just there. I broke off a dead polyp and the stalk appaears very brittle and soft too. I added a reactor, but if you seen my other post, I cant seem to get it above 350 even with an oversized reactor. I have started dosing alternately with turboCa, and Kalawasser but seems like it is very hard to get up for some reason.
Phan: I keep them about midway in my tank and I have ample light I think. 4 175HQ and 4x96w actinics. Maybe too much light is the problem.

Thanks for the help.

[EdKruzel]

I'm going to split this thread into the Chemistry Forum.
I'm sure Randy may have a cause for the low calcium levels.

Ed

[jfinch]

What is the pH of your tank water? Especially during the night time. I doubt it's a low calcium problem, 350 ppm is pretty low but I don't think it's causing this problem. The head is where the calcium is being consumed and you mention that the heads look fine. The stalk itself is dead skeleton. If it's stalk that's dissolving then perhaps your pH is low and/or maybe your alkalinity is really low (btw, what is your alk?).

[tacocat]

Are you dosing iodine? Fleshy corals seem to enjoy iodine now & again.

[Randy Holmes-Farley]

I agree that an important question is "what is the alkalinity?"

Also, I'm not totally clear on what is a stalk and what is a head in this context. Are you talking about parts of the solid skeleton, or the fleshy polyp?

[sjvl51]

What is your magnesium? I couldn't get my calcium above 380 - 400 until I brought my magnesium up.

Vickie