montipora loosing skin?

[likefish]

I have a 120 SPS tank with lots of acros and a decent colelction of acros. Connected is a 40 galon frag tank with multiple monti frags as well.

Yesterday i noticed the skin on one of my caps sloughing off in small areas. I looked further and noticed my an edge on my setosa turning translucent. 2 of my encrusting montis have small patched sloughing off as well.

Current water parameters:

SG 1.025
Temp stable at 77
Ca 445
Alk 7.0 (tested 2 more times and got 6.9 and 7.4)
Mag 1420
Nitrate 0
Phosphate 0 (hanna)

3 days ago i did a 20 gallon water change on the system. RO reads .1 TDS out of storage container. Using a batch of salt that has been in use for a while now. IO reef crystals.

I drip dose kalk spiked with vinegar. Same recipet has been in use for last year with same dose.

I ruled out montipora eating nudis by taking 2 of the affected frags adn dippind in bayer treatment, blew pieces off well and inspected water for anything left over. NO NUDIs!!!! :beer:

I upgraded my protein skimmer 3 days ago an it is breaking in nicely.

Acros, birsnest, and digis all look great with great polyp extension. Still have good PE on the affected montis as well.

I am considering doing another 20 gal water change but concerned that the change in parameters will further **** off the stressed pieces. I am going to slowly try to bump up my alk with a dosing pump.

If recession continues im going to frag off some of the healthy parts but would rather not. At 1.5 years old my pieces mare just now starting to look good.

Anyone have experience with this? Im stumped!

 

[Ted_C]

My reef tank has done the same.
http://reefcentral.com/forums/showthread.php?t=2324189

I've lost a lot of my higher end frags (15 out of 40 are gone). I thought it might have been the vermetid snails - I do have quite an infestation. I also thought some of them may have been annoyed by the aiptaisa I have breaking out.

I asked the same questions as you.

While I have no answer to your question and dont have answers to mine - I think mine was a combination of many factors: using IO reef crystals for the longest time, started running filter socks to try and starve out the vermetids (i.e. removing more nutrients), reducing my photoperiod from 13 hours to 9 hours (also resulted in less feedings and lower nutrients), switching to Red Sea Salts (tried both coral pro and regular) after being marketed and sold on the idea of the red sea system and then taking advice that the alk was to high in Reef Crystals and Coral Pro salt for a low nutrient system.

If I had to look at a single thing in your tank - your new skimmer may be releasing oils and volatile organic compounds from the manufacturing. Maybe try running a carbon reactor next to your skimmer output?

 

[likefish]

thanks for the info and link.

I ran the new skimmer in a 25% vinegar bath for several hours before putting it into the sump to avoid just such a problem. cant rule it out for sure though.

I have been carbon and GFO free for several months now. I have the reactors. Maybe put a small amount back online. I am trying to minimize changes in the tank. Nothing good happens fast and the corals like stability. That is my mindset as of now.

I m just wondering what i could have overlooked?

 

[Ted_C]

Did you open a new bag of IO Reef Crystals? It's hard to tell what goes into their batches - they may have gotten a bad batch of chemicals.