STN with polyps still showing?

[mic209]

So my latest order of frags have started to STN on me all of a sudden. Some of the corals still have polyp extension where the STN has occurred. Should I frag above the STN or let them be?

 

[Logzor]

If there are still polyps then the tissue has bleached out. If necrosis occurred, then everything in that area will be dead.

How slow is the tissue necrosis? In cases of RTN you definitely want to frag. In the case of STN you might be able to wait it out. If over half of the coral is gone I would definitely frag it.

Something in your system is off balance. Alkalinity, salinity, temperature. Make sure those are correct.

 

[mic209]

Well due to a bad batch of refractometer calibation fluid I had to adjust salinity, from 1.031 down to 1.025. I did it over a course of 4 days, might of been 2 fast. Seems like the STN is at a standstill now. All my other parameters are in line.