SPS Flesh Peeling/lifting from Skeleton

[treehugger]

Hey Kevin-

I'm hoping that you might be able to shed some light on an issue I've seen in one of my SPS aquaculture tanks. The total system volume is 1600 gallons and has been running for 3 years now. We have an "open ocean" tank that is 100% dark and makes it easy for us to do large h2o changes, a 120 gallon refugium, a 300 gallon tub of high flow Liverock, and a mangrove tank. The coral tanks are split up based on types of coral ie LPS, Softies, SPS, and a mixed 8'x4' flat with a 2.5" sandbed. All the systems are tied back into a common sump and flow to each tank depends on what is being kept in it. The highest flow goes through the flat as that is the primary tank for aquaculture. We do weekly 300 gallon water changes with a mix of H2Ocean and Brightwell salt (I find the two mixed together gives me great parameters). We have a mix of metal halide and t5 lighting over all of the tanks and they get 6 hours of full light each day. I know that might seem like a short light cycle but we've had great growth/success for the last 3 years on that cycle.

Parameter: Tested every other day and dosed to correct if necessary with bulk DIY.
Alk: 8.5-9.5 dkh (almost always hangs in that range)
CA: 400-430 ppm
MG: 1320-1375
NO3: 0
PO4: 0-0.03 after a heavy feeding
SG: 1.023-1.025
Temp:73-76 We've found the Australian corals like a cooler temp so we typically shoot for 75 but there can be some variation over night or on hot/cold days but never out of this range typically.

We feed a mix of reef plus and various frozen and dry foods twice a week and dose Iodine several times a week as this usually tests low although I question how accurate the salifert tests really are. Carbon is changed once a week and we Do not run GFO.

I've noticed lately that fully encrusted frags of a few SPS species were randomly blowing up basically over night. Upon closer inspection, I've noticed that the flesh seems to be inflated away from the skeleton and if you wave at it really hard, it just blows off. Sometimes the recession starts at the base but mostly they inflate and blow up within 24 hours. I've dipped several frags and have found nothing in the way of pests. I've tried moving frags into different areas of the system to try increased/decreased light/flow and it does not seem to make a difference. It seems to be isolated to 2-3 species for now. I've never had anything like this happen before and can't seem to find any info from surfing the web. Any advice would be welcomed.

Thanks in Advance,

Jeff

 

[kevinpo]

Hello,
I think most SPS keepers would like to maintain your water parameters The numbers you have posted are pretty much identical to what I recommend and run. Good job, and I don't think that 6 hours of full light is too short.

I don't like to keep soft corals with LPS and SPS in the same system but with the large water changes and the carbon you run the chemical warfare should be reduced. It sure sounds like allelopathy to me. I run ozone on my SPS systems and turn it on and off using and ORP probe controller set to an ORP of 390.

One test you could do is move a frag of the same species coral you have been experiencing trouble with into a separate system. Or move one that starts to lose tissue and see if it stops. Are the corals affected near each other physically? This could indicate a predator. Night observation can be another way to spot predators, although your description of the problem makes this scenario seem unlikely.

Disease is another possibility but should manifest itself if the coral/s is moved to isolation.

IME large areas of tissue loss have been due to high temperature spikes or sudden increases of light intensity (such as adding new bulbs, changes in kelvin rating, increasing water clarity, etc.).

Regards,
Kevin
PS: I haven't added iodine supplements since 2000.

 

[treehugger]

Hey Kevin-
Thanks for the quick reply. We isolate the different types of corals and systems as much as possible to cut back on chemical warfare by running all water through the skimmers/carbon etc before it recirculated. Each tank also has carbon running on it to help reduce the amounts in those systems (especially the softy and euphyllia heavy tanks) before it goes back to the main system. I wanted to add that these corals have been fragged for well over 6 months now as they were the start of a new round of mother colonies. The ones that have had the issue are near each other but there are many other types right near them as well that don't seem affected at all. I've watched for signs of predation but there does not appear to be any. We did replace the bulbs about two months ago but the issue did not arise until well over a month after the switch. We change bulbs about every 9 months and corals are placed according to the par range we have found them to enjoy. We monitor these ranges as it helps us when we move colonies into our service account tanks so there is an easier transition for the corals and less risk of issues or browning.

I think I may have partially isolated two issues, iodine and strontium. I know it is unwise to dose without accurate testing capabilities and I guess I should have trusted my instincts with the test kits available and the results I was seeing. As I was questioning the accuracy of the salifert test kits, I sent a sample out to a lab for analysis. According to their results, our Iodine was on the very high end of things .15mg/L as was our strontium at 15.8mg/L. Obviously we had stopped with the additive when we saw issues arise in the first place so that we could begin isolating potential causes. We never add strontium however so I was surprised to see this level elevated especially given how heavily stocked our system is and the coraline growth we see. I'm assuming the combo of high strontium and Iodine is affecting the coral flesh and these SPS are most likely the canaries in the coal mine. We've decided to increase our water change regiment over the next couple of weeks to 350 gallons weekly to try to get these levels to an acceptable amount.

Would you agree that the elevated iodine and strontium could be affecting flesh and causing the issue that we are seeing? Some of the pieces did seem to recover if they were fragged appart immediately upon any signs of distress. Hopefully we can work through this issue and again I really appreciate your input.

Jeff

 

[kevinpo]

Hello,
I'm fairly confident that lighting is not the issue. Too high of light and the corals will respond in hours not months. Too low light and the corals might change colour or grow slow but will not die. I have found it quite surprising under how low light levels corals will live (and actually do quite well under).
Chemistry however is quite another matter. For SPS corals especially good water chemistry is hard to achieve and maintain. You can't see it and the tests kits for the average hobbyists that are available are, in my humble opinion marginal.

Considering Strontium averages 8.1 ppm in natural sea water and iodine only .064 ppm iodine is going to be more difficult to measure accurately with the typical hobby test kit. This inability to accurately measure and regulate iodine can lead to toxic levels. The levels of iodine usage and retention/storage vary greatly among different coral species so the effects of high iodine levels could range from toxic to no noticeable effect. To make measurement more difficult the iodine additive is most often a solution of iodine and potassium iodide in water (like Lugol's solution) so most kits measure total iodine iodide concentrations. This solution is typically used as a sterilization and antiseptic agent so elevated levels are toxic to most organisms.

I would venture a guess iodine/iodide is your culprit but will quickly lower without more dossing. In the last 12 years of not dossing iodine/iodide I have not observed any negative results. Feeding red marine algae to fish will add some iodine/iodide to your system at quite safe levels.

Regards,
Kevin

 

[1guydude]

I've heard leaving the Exoskeletons from your inverts moltes will do the trick as well. I don't test nor dose for iodine but have also heard of people dosing 1drop of over the counter iodine for every 20g once a week. Any thouths kevin on the over counter stuff or are u stuck on no iodine supplements are needed? I pefer w/c's to supplement my tanks!Sry not trying to hijack.

 

[kevinpo]

Hello,
From my experience I would not recommend dosing iodine unless you can get your hands on a test kit that can accurately measure it +-.01 ppm.

Cheers,
Kevin