SPS bleaching Problem

imaan · May 27, 2016

Hi everyone
As you can see in the picture, one of my sps has started bleaching since one month ago. It has been attached in the current place since start day and had a lot of growth. My tank's phosphate is 0.01 by Hanna Phosphorus 736 , nitrate is 1 - 2 , calcium is 410 , mg is 1250 , just KH have had fluctuation between 7 to 10 from last week. ( Test kits are Salifert ). It is worth noting that some polyps open in bleaching area. Do you have any idea why it is bleaching while its open polyps and growth.

jsker · May 27, 2016

I run my Po4's at .02ppm and my No3's at around 4 to 5 ppm you need phosphates and nitrites. which could mean that they are hungry and need to be feed. I also dose amiona acids and that seem to help also

Diesel · May 27, 2016

It's a little bit of both but can be bad for SPS.
You're lucky that yie don't have a delicate SPS type, if so it might be a goner.
What you see is due to a large swing in ALK and on top your nutrients are to low for that level of ALK you have.
Low nutrients means low ALK.