My water parameters are as follows: Salinity - 1.025 Temperature - 80 pH - 8.0 Ammonia - 0 Nitrite - 0 Nitrate - 20 Phosphate - 0 Calcium - 480 dKH - 9.6 Magnesium - 1290 I will try and get it up ASAP. The mark is so small though I am sure it will not show up on a picture. This sounds very possible. I hope this is true because I am starting to get discouraged with SPS. Have you ever had any SPS die on you? I run Seachem Renew and Seachem Phosguard. It is at 9.8. So being frustrated, as you know I can get, I took the mother colony out and fragged off all the branches that looked like RTN. I then took a few healthy looking branches and glued them to a rock and put the mother colony on my sandbed for further observation.