Background: I am just getting started with SPS in my system that is one year old. I have about 13 frags most are doing great but a few have started to STN. The oldest frags are almost 2 months old with the newest being about one week in the system.
Question: All parameters have been very stable except last Monday I tested phosphates at .17 so I put a 25gal bag of Chemipure Elite in my sump (my tank is 200G total water volume). In 6 days my phosphates dropped from .17 to .9. Is these too much change too fast? Possibly causing STN? Any and all opinions welcome.
Question: All parameters have been very stable except last Monday I tested phosphates at .17 so I put a 25gal bag of Chemipure Elite in my sump (my tank is 200G total water volume). In 6 days my phosphates dropped from .17 to .9. Is these too much change too fast? Possibly causing STN? Any and all opinions welcome.


