Mobile Bay Reef Keepers

Okay, so I noticed that a couple of my corals were looking a bit wonky; Monti caps had bleached spots, Acros stopped growing etc.
I tested my water and (I'm typing from work so I don't remember all of my numbers) but this is what I found:

Alk is very high--over 4.5 meq/L (Hanna)
Mg a little low--just over 1300 ppm (Red Sea Pro)
Temp-- 82
pH--8.1
NO3--0.00ppm (Hanna)
PO4--0.00 (Hanna)
S.G.--1.026

but..........

Ca+--low 330's ppm (Hanna)

So my overall question is two-fold.

Would my corals take a huge dive due to the low Ca+, and why would my Ca+ be low with the Alk and Mg being high to normal?

This morning I noticed that the two Monti caps have very large dead spots, most of my Acros but one in particular has bleached a lot, and one of my Psammocpra has either completely bleached or is dead. Have also lost one of my Goniopora.

Help?!?!?

Okay, how are you supplementing CaCO3? Reactor, 2 part? Have you done a water change recently? Has anything at all changed recently or any other recent maintenance tasks? I don't see the parameters as immediately problematic, but they should be corrected when possible. Do you do any form of organic carbon dosing and/or other additives? If so, elevated alkalinity is problematic. Have you tried another test kit to verify the more recent results? Before jumping to change too quickly, I would try that first as soon as possible.

Also, what salt are you currently using and has that been tested/verified when mixed?

I use two-part based on the Randy Holmes-Farley formula dosed once daily into the sump. I also run kalk in my ATO. As far as a water change I've not done one in three weeks (behind one week). I do not dose organic carbon, but do use a product from TLF called Acro Power. But I have not dosed it in a week since when all of this seems to have begun, my RBTA died and my nutrient load as gone up (evidenced by the skimmer cup).

From the beginning I used IO salt, but about 6 months ago I switched to Aqua Vitro.

The alk reading is accurate--I checked it with my Hanna then to verify that I checked with a dip strip (I know they suck but good for a quick idea)--I plan on testing a third time with my Red Sea Pro kit to triple check.

Check anything in the system that could possibly corrode--all magnets, powerheads, etc. While I don't usually recommend large water changes, this sounds like a good exception as a test. Do you have or use any activated carbon or adsorption resin?

As far as how the CaCO3 parameters became skewed, have you tested the AquaVitro after mixing/use? Are you dosing manually or is it automated? Both the 2 part and kalkwasser are balanced, so should not cause that by themselves. Something somewhere caused them to skew, which could be anything from the salt mix to overcompensating one parameter, etc. At one point, could there have been precipitation that you were unaware of and you only noticed the lowered alkalinity (and subsequently raised it)? How has the pH been with kalkwasser dosing and how have things been since evap likely rose during the summer? Just trying to think of as many things as possible that could have occurred.

I do need to do a WC anyway, so now is a good time. I do have GAC that I just started running today as well. One good thing I've noticed is that my skimmer isn't producing as much skimmate so that tells me that the crap in the water is being reduced.

I have not tested my mix water, but I do need to. I did that several times in the past when I was still using IO.

I dose manually until today as I brought my dosing pump online. One thing about my two-part is that (I think I mentioned this) is based on Randy Holmes-Farley's recipe. One thing I do differently is that that I use dry SeaChem advanced calcium powder for the Ca+ part. All I can think of is that I didn't mix it to the right concentration, and even though I was dosing, it wasn't enough to keep up. My levels and corals would have been fine until I reached the point of much too low and that is when things started bleaching/dying.

I have to admit (hard pill to swallow) that I have been lazy in testing because so much else has been going on, so I'm sure had I done this like I should have I would have caught this sooner and not be having this discussion.

As far as the kalk goes, I've been very lucky. My tank had always been on the lower side of the pH scale and I tried forcing it early on to raise it, but it wouldn't stay, so I said screw it and let it run. When I started running the kalk my pH now stays constant around 8.1 even during summer. We keep our house cool anyway, so it's not bad.

Hmm, never used the Seachem product. I looked at its info page and found the MSDS. Seems like a blend of various chloride salts. I only use anhydrous calcium chloride with a high purity. Depending on the Seachem product's ratios, it likely won't mix to the appropriate concentration with respect to calcium, unless you could find out how much is in it. Then you'd have to match 20 ppm Ca++ to each 1 meq/L alkalinity added. That's how Randy's recipe is calculated, anyway and is how it is balanced. You could still do it, but it just seems like a lot of work.

You aren't alone about testing. I actually only have an alkalinity test anymore :/. I haven't tested anything else in a good while.