New acros "turning to stone", while established acros doing fine

[Crashjack]

I've got a weird situation where new acro frags die appearing as if they are turning to stone, mostly from the base up and happening pretty slowly. The skin doesn't slough-off, and the coral doesn't bleach. It looks like as if the skin is drying-out and then hardens. The acros I've had for some time are mostly fine, though I did lose a colony several months ago, which exhibited the same symptoms. Another strange thing is that my acros have always encrusted much more then they grow upwards. Also, some of my zoas haven’t been opening as well as they used to, and my chaeto doesn’t grow like it used to even though my nitrate/phosphate levels are elevated.

My tank is 6’x2’x19” with an estimated 125 gal actual water volume, and I perform 20 gal water changes every two weeks (regular Instant Ocean salt). The tank has been running about four years. My lighting is a 5’ 6-bulb ATI LED Power Module Hybrid wifi ((4) LED clusters and (6) 80w T5 bulbs). My flow comes from (2) Gyre XF250 powerheads.

I recently got an ATI ICP Analysis (below), which showed very high iodine (1,600 ug/l), elevated lithium (509.8 ug/l), somewhat elevated nitrate (18.12 ppm) and phosphate (.31 ppm) and maybe carbonate hardness a little low for my nutrient load, measuring 8.04 dkh. The ICP test also showed trace elements such as manganese, iron, and zinc, as undetectable. My pH runs between low 8.0’s (early mornings) to low 8.3’s (late afternoons). My tank has always had a grounding probe, and I recently tested for stray voltage with none detected. With the coral issues and knowing my chaeto wasn’t growing well, I started dosing Brightwell Aquatics Chaeto Grow about a week-and-a-half before I took the ICP samples so I was a little surprised I had so many undetectable trace elements, especially since I also run a Ca reactor, which should be contributing to trace elements.

My only explanation for the high iodine is that I was dosing Two Little Fishes Sea Elements weekly, and I presume it contains iodine (elements aren’t listed so I’m guessing). Chaeto Grow lists the elements and doesn’t list iodine. I also feed ½ sheet of Sea Veggies (nori) 2x per week, which is likely high in iodine, though I don’t see how that could affect 125 gallons of water. Other foods are LRS, Rods, PE Mysis, frozen brine, frozen fish eggs, Prime Reef flake, freeze dried mysis, and Hikari pellets. I also add Selcon to my flake/freeze dried mysis mixture, which I feed 3x/week, but Selcon doesn’t list iodine.

I don’t know if the high level of iodine is a factor or even if it is an accurate reading. I’m pretty much baffled, and any help is appreciated.

Affected acro "turning to stone" (you can see the colony that died-off on the left and unaffected acros behind).

Affected zoas

Unaffected acros/SPS (plus a happy trigger).

ICP Analysis

 

[IKD]

Your phosphate is reading .31 (if I’m reading that correctly). That seems a bit high (especially relative to Nitrate at 18. I suggest bringing that closer to .05-.10 range.

 

[ZoWhat]

Welcome to the Unforgiving World of Acros

No need to cry and shout
Just turn dem pockets inside out
Buy more Acros
We'll make more

.

 

[blasterman]

I don't have evidence but this seems to fit my usual SPS acclimation scenario of nutrient doom.

You have relatively high nutrients with phosphate being an eye opener. 18 nirate is fine....for an older established tank.

Most volume fraggers run very low nutrients to keep low maintenance tanks. When we to take SPS from those tanks and put them in 18 nitrate and .3 phosphate its RTN city. Phosphate is adrenalin for zooanthalae and the coral burns itself up. Being on to this little dilemma I recently added some acros from an online seller and backed down my nutrients before hand.. I tested his bagged water the corals came in and nitrate and phosphate were just a trace. By adjusting my nutrients ahead of time the new frags didn't flinch after a brief quarantine. I realize though this can be hard to do with a large tank.

SPS sellers need to start posting nutrient params to resolve this issue or we will keep killing coral.

 

[Crashjack]

Your phosphate is reading .31 (if I’m reading that correctly). That seems a bit high (especially relative to Nitrate at 18. I suggest bringing that closer to .05-.10 range.

I don't have evidence but this seems to fit my usual SPS acclimation scenario of nutrient doom.

You have relatively high nutrients with phosphate being an eye opener. 18 nirate is fine....for an older established tank.

Most volume fraggers run very low nutrients to keep low maintenance tanks. When we to take SPS from those tanks and put them in 18 nitrate and .3 phosphate its RTN city. Phosphate is adrenalin for zooanthalae and the coral burns itself up. Being on to this little dilemma I recently added some acros from an online seller and backed down my nutrients before hand.. I tested his bagged water the corals came in and nitrate and phosphate were just a trace. By adjusting my nutrients ahead of time the new frags didn't flinch after a brief quarantine. I realize though this can be hard to do with a large tank.

SPS sellers need to start posting nutrient params to resolve this issue or we will keep killing coral.

Nitrate/phosphate were a little higher than normal. For probably 6 weeks prior to taking the samples, I had reduced my skimmer's water level to the point where I was skimming almost nothing. Reason being, several corals were looking starved in that they weren't inflating or opening up as much, and didn't even look quite as colorful plus my chaeto wasn't growing at all. I also had virtually no micro algae in the tank and not even much on the glass, and my coralline algae wasn't as healthy looking or spreading like usual.

I also thought I might be low on trace elements such as iron for the same reasons. Hence, I started dosing the Chaeto Grow because it contains a lot of trace elements, and I figured I might back into my coral issues by getting my chaeto to grow. I also started dosing live phytoplankton a month or two before I took the samples. Even with nitrates and phosphates this high, I still don't have much micro algae growing in the tank. What seemed to increase algae growing on the glass was the addition phytoplankton. Anyway, I am increasing my dosing of Chaeto Grow and am also going back to heavier skimming. Chaeto Grow includes carbon so I'm hoping that coupled with the heavier skimming, phosphate levels will go down some. That said, I've battled Dinos twice, and I'm not interested in extremely low levels of nitrate /phosphate.

The nutrient levels in commercial tanks is a very interesting prospect. We seem to worry a lot about lighting and maybe calcium and alkalinity levels in these commercial tanks, but no one ever mentions nutrient levels. I suspect my acros that have been in my tank for some time and are doing well have become accustomed to whatever my problem is, be it low levels of trace elements, high phosphate levels, or maybe even some bad bacteria that the new acros can't fight off. What is odd to me about the acro deaths is that the skin doesn't slough-off, and the coral's don't bleach; they just seem to slowly die from the base up with the skin intact. I guess another possibly is a bacteria causing the problem, and it is leaving a residue that appears “stone- like”.