Help - What is this growing on my rock work?

[Taggerz28]

Hi All,

Had some major issues this year with my 5 year old reef tank where it seemed to crash, lost nearly all my SPS corals. Still not entirely sure what caused it but the corals seemed to create stress mucus and all got STN. I initially put it down to a bacterial infection as one of the changes I made was adding a new bacterial additive, but who knows.

Anyway while the tank is practically empty now I’ve noticed a lot of this grey clingy detritus looking things growing on the underside of my rockwork. Some near the few sps corals I have left on the base and possibly contributing to killing the sps. Not entirely sure what it is and would appreciate a steer in the right direction on what it is and how to combat it.

I brush it off and it comes back. It grows mainly on the underside of rocks (low flow/light areas?). Initially thought type of hydroids due to death of nearby corals but don’t really look like them. Flow is generally fine, x2 MP40s and x2 Nero 5s - all on about 50% in my 400 litre system.

Parameters within ideal ranges apart from Nitrate which has crept up to nearly 30ppm, phosphate is 0.07. Alkalinity 8.2, calcium 1400, magnesium 1200 (need to raise).

Stopped feeding aminos and coral foods along time ago and reduced frozen feeding for the fish (fish are fine). I also switched salts from Nyos to Aquaforest for 2 months at the same time as adding new bacteria. Since switched back to Nyos. UV was taken offline too after reading conflicting advice about running them 24/7 - should I put this back on to help?

Photos show the issue on/around corals June and the other photos taken yesterday showing increase.

Thank you

 

[nautical_nathaniel]

I'm not sure what it is exactly, but in my mind that's just natural "growth" like an algae or a sponge and not necessarily good or bad. I don't believe it would have contributed to your coral loss unless it's poisonous or somehow able to sting corals.

 

[Timfish]

There's lots of stuff that likes low light areas. It could be some kind of sponge or forminiferan or something else. I see something that looks the same in most of my tanks and it does like to trap detrutus. My guess is the stuff more noticable or grown more due to more nutrients available as there are fewer corals feeding. I would focus on getting the system back to where you have good corals growth but if they bug you you could use steel straws to remove the detritus and reduce thier numbers. To help with the microbial equilibrium you might consider adding some ocean sourced live sand or live rock. Another alternative, if you know other reefers with good coral growth, is do some water changes with clean water from their system. Bottled bacteria are fine but keep in mind only a tiny percentage of the microbial stuff on reefs can be cultured and stuck in a bottle. Ocea sourced live sand and/or live rock will have a lot more diversity. Here's a couple links if you want a rabbit hole to go down. :D

"Coral Reefs in the Microbial Seas " This video compliments Rohwer's book of the same title. Used copies are available on line and it may be free to read on Internet Archive. Both deal with the conflicting roles of the different types of DOC (carbon dosing) in reef ecosystems and how it can alter coral microbiomes. 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 and are an excellent starting point to understand the conflicting roles of Dissolved Organic Carbon (DOC, aka "carbon dosing") in reef ecosystems.


Delbeek Molar Ratios


Changing Seas - Mysterious Microbes


Microbial view of Coral Decline


Nitrogen cycling in hte coral holobiont


BActeria and Sponges Jones


Maintenance of Coral Reef Health (refferences at the end)

 

[Mr. Mojo Rising]

There's lots of stuff that likes low light areas. It could be some kind of sponge or forminiferan or something else. I see something that looks the same in most of my tanks and it does like to trap detrutus. My guess is the stuff more noticable or grown more due to more nutrients available as there are fewer corals feeding. I would focus on getting the system back to where you have good corals growth but if they bug you you could use steel straws to remove the detritus and reduce thier numbers. To help with the microbial equilibrium you might consider adding some ocean sourced live sand or live rock. Another alternative, if you know other reefers with good coral growth, is do some water changes with clean water from their system. Bottled bacteria are fine but keep in mind only a tiny percentage of the microbial stuff on reefs can be cultured and stuck in a bottle. Ocea sourced live sand and/or live rock will have a lot more diversity. Here's a couple links if you want a rabbit hole to go down. :D

"Coral Reefs in the Microbial Seas " This video compliments Rohwer's book of the same title. Used copies are available on line and it may be free to read on Internet Archive. Both deal with the conflicting roles of the different types of DOC (carbon dosing) in reef ecosystems and how it can alter coral microbiomes. 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 and are an excellent starting point to understand the conflicting roles of Dissolved Organic Carbon (DOC, aka "carbon dosing") in reef ecosystems.


Delbeek Molar Ratios


Changing Seas - Mysterious Microbes


Microbial view of Coral Decline


Nitrogen cycling in hte coral holobiont


BActeria and Sponges Jones


Maintenance of Coral Reef Health (refferences at the end)

thank you for sharing these videos, I do watch them all, appreciate it!

 

[Fish Fan]

I think you have more than one organism growing there, but the first couple pictures to me seem like they could be Byopsis, which is a tough pest to deal with. See if it looks anything like what's in this article:
https://www.bulkreefsupply.com/cont...zxRgMwH55duVTBs8BKggZMdrY2Sm_sixnwBRfZN9AAyiq