I hope this can help someone out in the future. Before my tank changeover, I noticed that my green birdsnest was exhibiting STN from around the center of the colony. The colony had gotten rather large so I was hesitant to frag it as it did not appear to be RTN. Checked all my parameters and everything was where it should be, salinity was at 1.026, pH 8.1 with very little deviation per my Apex log, no ammonia, nitrite, nitrate, or phosphate that could be detected, Alk was 8.5, Ca 430, Mg 1450, temperature stable at 79 +/- 1 degree max according to my Apex log.
Well, the STN spread and I finally got to the point where I took it out to frag the parts that were still doing okay. It was then that I discovered what had happened. The colony had that sewage smell of decaying matter and I found an Astrea snail that had fallen and gotten wedged near the center of the colony. It was stuck in there pretty good and I couldn't get the shell out without breaking off some branches. Lesson learned to pull something in the future so I can check for this.
Good news is I had plenty of branches that were doing fine and the thing grows like crazy so I'm sure it will be back to softball size in no time from just the frags.
Well, the STN spread and I finally got to the point where I took it out to frag the parts that were still doing okay. It was then that I discovered what had happened. The colony had that sewage smell of decaying matter and I found an Astrea snail that had fallen and gotten wedged near the center of the colony. It was stuck in there pretty good and I couldn't get the shell out without breaking off some branches. Lesson learned to pull something in the future so I can check for this.
Good news is I had plenty of branches that were doing fine and the thing grows like crazy so I'm sure it will be back to softball size in no time from just the frags.