*help* with STN

[Blake_Cond]

Hi All!

My Acropora Prostrata has STN :headwally:, all my water parameters are fine.
Salinity: 1.025
Ammonia: 0ppm
Nitrite: 0ppm
Nitrate: 0ppm
Calcium: 420ppm
Alkalinity: 11 dKH
Phosphate: 0.25ppm
Magnesium: 1350ppm
So l see that everything seems to be fine for SPS, before these parameters my nitrates were high (20ppm) and phosphates (2.0ppm). I have been using Red Sea NoPox and added some Macro algae so maybe these sudden changes to the parameters caused the Acro to get STN. But the strange thing about this necrosis is that it only occurs when the lights are out which makes me think that it's some sort of parasite that caused the STN. I can't see any AEFLW or red bugs. The coral is showing polyp extension as it has since l have purchased it. Any thoughts or tips would be great! Cheers Blake.

 

[popsock]

Hi, How quickly did you drop the nitrates and phosphates? And yes that's a good explanation for the STN. I always advise to keep nitrates about 2-3ppm there's no advantage at all in having is zero and you'll often hear of problems re. zero nitrate.

You should also get that PO4 down to <0.03ppm eventually.

 

[swk]

*help* with STN

Alk may be too high with that low of nutrient levels. Just something to consider. I have low nutrients myself and if I get over 8 I start having stn. I run mine around 7 with nitrates of about 1 and po4 at .03

 

[PaleHorse]

Eliminate one problem at a time if you think you have bugs use bayer. If you think your alk is high lower it. If you have a ulns then I would feed more and see if any changes occur. But one think at a time and take it slow so you identify the problem