Zoas not opening

[twychopen]

Ok, this goes back to my zoanthid thread but i want to figure it out for future sake. I am trying to figure out why my Calcium is so low. I have a few pieces of chalice or montipora ( :( i dont know which, they are tiny) that have completely turned white. They seemed to be doing fine a few weeks ago. Also, the zoanthids that I have had for a month or so are doing a lot better but are not spreading, and I actually see a spot that seems to be receding. They all are very deep in color and opened, and have grown in length since I got them but I am just curious as to why it seems like no coraline algae is growing (I have rocks that have it on it that I have put into the tank) and the corals are doing strange things. (I also have a xenia that pulses but the "fingers" are curled.) I am trying to be patient and not dose anything but the ph is 8.3 and salinity is 2.028, temp 80.2 no Nitrates, Nitrites, Ammonia, or Phos. The only things that seem to be low is Calcium (around 350 and magnesium 1150). I have change about 15% of water every week.

I have the stuff to dose but I don't want to unless absolutely necessary. I have been reading up to try to figure out whether or not to dose. Here are the instuctions from BRS. http://www.bulkreefsupply.com/store/Recipe-1-Instructions-for-Bulk-Packaged-Materials

[Europhyllia]

I don't know if I oversimplified this but basically I started to dose when stuff got depleted faster than I was replenishing it with 10% weekly water changes.
Kalkwasser has been an easy solution for me (timed ATO) but I also use two Salifert products in addition to that. For some reason my clams and coco worms seem to be really into building scutes and tubes and they appear to be sucking the stuff right up.

[twychopen]

Yeah that makes sense, but I just don't know what could be depleting it so quickly. I have 7 polyps on a hammer coral, a few small zoanthids, a pulsing xenia and thats it. I haven't even seen the start of coraline algae :(. I think it just doesnt start out very high.

[stoneroller]

What are you using to measure salinity? Your salinity is a bit high at 1.028. I shoot for 1.025.

Why are you convinced that your calcium is being depleted at a fast rate? 350 is not a bad place to be on calcium given your current demand (a few softies).

Just try adding a little iodine to see how the xenia respond. That should open them up for you.

Coraline will take some time to start covering surfaces. Someday you'll be cursing it while you scrape. Patience....

[twychopen]

I use a refractometer. Well when my salinity was lower the corals seemed to not like it as much. Im don't necessarily thinkthat it is being depleted quickly, I think it may start off low to begin with. I tested last night and the Calcium was around 320. How much iodine? I have read that you can easily overdose iodine. The weird thing to me is that the zoanthids are gaining color and growing longer, but they seem to be shrinking in colony size. If you look at the first picture, the zoanthids that are by themselves on the corner are now completely gone. Daniel is coming by on Saturday if it works out and hopefully a more experienced reefer will give me a good idea of what I am looking at

I'm just gonna cross my fingers on the coraline algae. I am hoping it only covers the back glass hahaha. jk i know that thats not gonna happen.

[stoneroller]

Just follow the directions on the iodine