White bare spots on hard coral

jlmawp

New member
Anyone have any idea what might be happening here? This coral has been happily growing for a long time now, with no changes to water or environment. I had been out of town for several weeks with a trusted person feeding the tank regularly while I was gone. However, I suspect this may be the work of the couple hermits I have getting curious and hungry in my time away.

Any other thoughts on what could be causing these white spots?
 

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Hmm has it gotten worse? My first guess would have been STN. Any new additions recently that may have brought a pest in?
 
Nope, nothing new has been added in well over a year.

I just got home a few days ago, but seems like a few more spots have shown up since then. The spots are picked clean. There doesn’t appear to be any “flesh” on it that looks unhealthy. All polyps are fully extended and it has good color otherwise.
 
This can be very frustrating and hard (impossible) to stop. I have it going on with a frag in my tank.
 

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What are your water parameters especially phosphates? What are your PAR levels? Are you carbon dosing? I doubt it's your hermits but more likely low phospahtes or excess labile DOC (carbon dosing) although it's impossible fo rus to test for the later.
 
Was quite busy yesterday but ran full tests today.

Ammonia: 0
Nitrite: 0
Nitrate: 0
Phosphate: 0
Mg: 1090
KH: 5.7
Calc: 360

I'm a little low on the stony coral big three (which is being fixed now), mostly because I didn't burden my friend with doing the more complicated supplementing while I was gone, just the feeding. The params are otherwise good.

I did notice one thing, though. The thermometer had come loose from the glass and stuck itself right at the base of this coral. I took it out to clean it, and when I set it down in a bowl, its tip shattered instantly with very little impact, spilling the little beads everywhere. I suspect it was already cracked. I'm not sure if a leak of a thermometer would affect a coral like that, but the worst of the shedding is happening right where the tip of the thermometer was.

I can't express how little I do to this tank and how consistent I am with topping off and doing water changes. I do parameter checks much less often than a few years back because it just stays so consistent. No light changes in the last 2 years either. I run a tight ship so I don't have to worry about variables! This coral grew from a half-dead little 1-inch frag my sister gave me to what you see in this picture over 4 years or so. Slow and steady growth over that time and has never shown a single weakness or issue like this. It's quite hearty and happy usually. Something drastic happened, and I'm wondering if it was the thermometer break.

I am doing a 3 gallon water change (10 gallon nano), and doing a decent cleaning. Cleaning the filter sponge, scrubbing the jets, and replacing the carbon pellets. I'll get levels to where they need to be and hope for the best from here on.

Any other ideas would be appreciated, particularly around the thermometer part.
 
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Yes, but the paper seems to apply more to overall oceanic processes, see Rhower's book mentioned below. In our systems it's easy to disrupt the microbial processes that deal with labile, semi labile and refractory DOC. On reefs labile DOC is roughly 1/3, a small percentage of semi-refractory DOC and roughly 2/3rds refractory DOC which is generally not able to be broken down in healthy reef systems. When excess labile DOC is produced by nuisance algae (including turf and macro alga) or added with carbon dosing heterotrophic bacteria can proliferate by feeding off the refractory DOC with the use of the labile DOC. Unfortunately this can have a negative influence on corals in two ways. Growth of heterotrophic bacteria in coral microbiomes can reduce the oxygen levels in the surface mucus layers effectively sufforcating corals, and/or the excess labile DOC can promote pathogenic microbes in the coral mucus layer directly causeing diseases. Keep in mind this is a very simplified explanation. It's complicated by species and genotype differences in immune systems of corals as well as cryptic sponges processing labile DOC (some processing it 1000X faster than bacterioplankton removed by skimmers) and processing labiel from corals differently than algal labile DOC. Keep in mind this is a very simplistic expalnation. :/

I asked about the phosphates as the level you posted is below the threshold level identified by Southhampton University to prevent phosphate limitation which can cause bleaching. You mention you've been doing thing the same for years. One consideration is your corals have grown but you haven'e increased your fish load of feeding to compensate with the increased need for nutrients. Easiest thing to do would be to increase how much you can feed your fish but this has obvious limitations. Directly feeding your corals may be a solution but keep in mind different species have very different requirements and what one likes another certainly will not.

Here's a data bomb. :)

"Coral Reefs in the Microbial Seas" This video compliments Rohwer's book of the same title (Paper back is ~$20, Kindle is ~$10), both deal with the conflicting roles of the different types of DOC in reef ecosystems. While there is overlap bewteen his book and the video both have information not covered by the other and together give a broader view of the complex relationships found in reef ecosystems
https://www.youtube.com/watch?v=-R2BMEfQGjU

Changing Seas - Mysterious Microbes
https://www.youtube.com/watch?v=c7hsp0dENEA

Nitrogen cycling in hte coral holobiont
https://youtu.be/DWItFGRQJL4

BActeria and Sponges
https://www.youtube.com/watch?v=-oLDclO7UcM

Maintenance of Coral Reef Health (refferences at the end)
https://youtu.be/dGIPveFJ_0Q

Optical Feedback Loop in Colorful Coral Bleaching
https://youtu.be/oadKezUYkJE

Richard Ross What's up with phosphate"
https://youtu.be/ZRIKW-9d2xI
 
Thanks a lot Tim. Lots to digest Timfish

I am curious how you run your tanks and how feed them. Have you discussed this already?
 
Timfish

I have been using this product in my newly setup tank. I would love to know your thoughts.

https://www.algaebarn.com/shop/aquarium-supplies/bacteria/pns-substrate-sauce/

What does PNS Substrate Sauce™ do?

Purple nonsulfur bacteria (PNSB) are extremely ancient microorganisms that are found everywhere on Earth from freshwater and marine sediments to moist terrestrial soils. They are notable for their adaptability, as they are capable of all four major modes of metabolism: chemoautotrophy, chemoheterotrophy, photoautotrophy, photoheterotrophy. This means that they may function similarly to nitrifying bacteria (chemoautotrophs), heterotrophic bacteria (chemoheterotrophs), or plants/algae (photoautotrophs). But they are most unusual, interesting and indeed useful as photoheterotrophs. As they consume organic carbon, they take up ammonia/nitrite/nitrate and phosphate as nutrients. While able to survive in virtually any environment, PSNB are "in their element" where there is little-to-no oxygen, at least some light and plentiful organic matter (deep sand beds, under live rock, within porous filter media, etc.). This makes them very much unlike "traditional" nitrifying bacteria which prefer dark, highly aerated environments and utilize only inorganic carbon sources (e.g. CO2). Thus, rather than competing with the nitrifiers found in typical biofilters, the PNS bacteria in Hydrospace™ PNS Substrate Sauce™ actually complement them. In so doing, they reduce the amount of time required to complete the nitrogen cycle in new aquaria! Additionally, unlike the aerobic nitrifiers, PNS bacteria can perform denitrification, converting nitrate into harmless nitrogen gas. May be used side-by-side with Fritz TurboStart! Fantastic for seeding live rock! The natural reef foundation:

As these bacteria grow, they become an excellent, natural live food source for corals. Stony and soft corals alike have been shown to directly consume PNSB, which are rich in protein, vitamins and color-enhancing carotenoids. Even more, they act as powerful probiotics! PNS Substrate Sauce™ is specially made for saltwater aquaria. And, it is completely safe, non-toxic and non-pathogenic. PNSB may vary in color from yellow to red to purple depending upon pigment content, which is determined by environmental and dietary factors; product color may vary from peachy-purple to orange-red. Pink to lavender bioflocculants (which may form in the bottle) do not affect product quality. Need a side of pods and phyto with the combo after you start stocking? Then check out the Ultimate Ecopack which contains pods, phyto and PNS YelloSno™ along with PNS ProBio™, a formulation of PNSB specifically adapted for use in mature systems! The benefits of PNS Substrate Sauce™ are numerous:
  1. It has an extensive shelf life.
  2. It is easy to measure and dose.
  3. It promotes rapid nitrogen cycling.
  4. It reduces the need for water changes and prolongs the life of chemical filtrants.
  5. It removes harmful ammonia, nitrite and nitrate.
  6. It is a highly nutritious food for many aquarium filter-feeders and detritivores.
  7. Its probiotic properties can reduce the incidence of disease in diverse aquarium species.
  8. Contains two ecologically important PNSB species: Rhodopseudomonas palustris and Rhodospirillum rubrum.
 
Are there known treatments Shane?

No known treatments for STN that I’m aware of other than fragging. That said, it’s starting to sound like that’s not what’s going on here. Looks like could be irritation from the thermometer (if it hasn’t gotten worse).

With yours, I can’t say for certain, but I’ve seen similar occur simply due to shadowing (when it’s mostly around the base)

My experience with SPS is very limited
 
I asked about the phosphates as the level you posted is below the threshold level identified by Southhampton University to prevent phosphate limitation which can cause bleaching. You mention you've been doing thing the same for years. One consideration is your corals have grown but you haven'e increased your fish load of feeding to compensate with the increased need for nutrients. Easiest thing to do would be to increase how much you can feed your fish but this has obvious limitations. Directly feeding your corals may be a solution but keep in mind different species have very different requirements and what one likes another certainly will not.

This is definitely a possibility, but I have several other corals in the tank as well. One other SPS (not dying, but not growing much), and several LPS and softies. None of these are doing badly and seem to be doing just fine, and they like nutrients and dirty water more than SPS do. Most serious SPS people do well to keep all nutrient traces out of their tanks, whereas I tend to let mine go where they will and take care of it with fairly regular water changes. No dosing, scrubbing, or sump. I'm just thinking that the LPS and softies would be suffering a bad fate way before the SPS if sulfates were indeed the issue here.
 
Thanks a lot Tim. Lots to digest Timfish

I am curious how you run your tanks and how feed them. Have you discussed this already?

Hmmm, I'm sure I have but I post on multiple forums so you'd probably spend a lot of time searching. :/

I try to keep them as simple as possible but with redundacy so if any one piece of equipment fails there's minimal risk of a system crashing. Ease of maintenance and access is my second priority so I'm not wsting a lot of time having to get to something or fix something if it fails. With these considerations I moved to just simple unlit sumps a couple decades ago and felt pretty well validated after seeing de Goeij's research showing cryptic sponges process stuff 1000X faster than bacterioplankton (the stuff skimmers mess with). For flow I try not to go over 10X per hour and am happy with 5X or 6X. As far as feeding I do mess with phytoplankton but won't use any of the prepared products availablle, there's too great a variation in species prefference and unless you're feeding a species specific system it's a real good chance feeding will have a negative impact on someone. If you want more stuff to read here's some links. ;)

Element cycling on tropical coral reefs.
This is Jasper de Geoij's ground breaking research on reef sponges. (The introduction is in Dutch but the content is in English.)
https://www.rug.nl/research/portal/f...letethesis.pdf

Sponge symbionts and the marine P cycle
https://www.pnas.org/content/112/14/4191

Phosphorus sequestration in the form of polyphosphate by microbial symbionts in marine sponges
https://www.pnas.org/content/112/14/4381

Differential recycling of coral and algal dissolved organic matter via the sponge loop.
Sponges treat DOC from algae differently than DOC from corals
https://besjournals.onlinelibrary.wi...365-2435.12758

A Vicious Circle? Altered Carbon and Nutrient Cycling May Explain the Low Resilience of Caribbean Coral Reefs
https://academic.oup.com/bioscience/.../6/470/2754308

Surviving in a Marine Desert The Sponge Loop Retains Resources Within Coral Reefs
Dissolved organic carbon and nitrogen are quickly processed by sponges and released back into the reef food web in hours as carbon and nitrogen rich detritus.
https://www.researchgate.net/publica...ce_Sponge_loop

Natural Diet of Coral-Excavating Sponges Consists Mainly of Dissolved Organic Carbon (DOC)
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3934968/

The Role of Marine Sponges in Carbon and Nitrogen Cycles of COral Reefs and Nearshore Environments.
https://search.proquest.com/openview...l=18750&diss=y
 
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