Figured I would give an update and provide a cautionary note.
I now understand RTN and STN a lot better. At least I think i do. I’d be willing to wager that the bacteria(s) or protozoan(s) that causes RTN/STN are always in our systems. These bacteria are likely normally benign. Its only when the colony is stressed from other factors do these pathogens have the ability to enter the host. I have also noticed that the rate of tissue loss appears to increase during a photo period.
This particular coral colony initially improved, had great polyp extension and color improvements. The frags that I extracted are still alive and well as of today.
The cautionary story.
Hurricane Ian, definitely created an issue in the system. I was unable to clean aquarium normally for a week, as a result, I had a massive algae bloom. I decided to use filter floss to wipe down the walls of the aquarium and apply filter floss to the power heads to clear debris in the water faster. Initially not an issue for the first week, when the second week arrived I noticed that some stringy algae was forming around some of the SPS tips. Very alarming. Removed a few pcs of algae from the tips of the sps and determined the cause. The filter floss became entangled in some of the sps coral colonies. This particular SPS coral colony was especially susceptible because of its tight branch skeleton structure. While I was able to remove 90% of the filter floss fibers from this particular colony, it was still adversely affected and stressed by the nuisance algae formation. Fast forward to 3 days ago, the section of the coral colony I was unable to extract the filter floss from started to have complete polyp retraction. As such, it started to RTN yesterday. I did proceed forward with the same protocol, hopefully some of these new frags survive.
In summary, the sps colony was not 100% recovered from the first stress event. Had two subsequent stressful events alk swing from hurricane Ian and filter floss entanglement as a result an RTN event occurred yesterday. I wont be using filter floss to clean the aquarium again.
An important but perhaps unrelated note, yesterday I dosed Microbacter 7. While I don’t have years of experience using this product, the short timeframe I have used it appears to have produced positive results concerning nuisance algae control and is not posed a problem in the past. I am however weary that the bacteria in this product may have contributed to the RTN event as the coral was already stressed.
Stressed coral with weekend immune system + massive scavenging bacteria addition = RTN? Will definitely avoid using bacteria products and will caution others on using any type of bacteria adding products or potential causing a bacterial bloom if an sps coral colony is stressed. It might just send it into RTN.
