SPS tips burning

[marreef]

Hey guys well im having a problem with my acros all the tips seem to be burning away like something is biting it but its not i stood literally for hours to see if one of my fish are pecking at corals but nothing, i have also gotten out of bed a 3am to see if there's some type of crab niping at the corals at night and again nothing i dont understand what is happening and my tank parameters seem to be perfect except for nitrates please give me some insight into what you guys might think the problem is.

salt 1.026
ph 8.2
ca 420
alk 8.0
mg 1300 and cant get it any higher
n03 15ppm and cant get it down
p04 undetectable
temp 77deg

 

[Alsshon]

How long has your tank been running now? Are the white tips spreading all over the corals or are they just staying as white tips?

 

[Finland]

Possible growth tips? Do you have a pic?

 

[Reef Bass]

Your parameters look decent. Bringing mag up is easy - simply dose. Bringing nitrates down below 15 can be more difficult. Your nitrates are not the cause of your alleged tip burn.

A pic would definitely help. You know the growing tips of corals are often a different color from the body, and sometimes white, right?

 

[marreef]

the tank has been running for a year now, i wish they were growth tips but unfortunately they are not the coral is the same size and i do know what growth tips look like whats actually happening is the skin of the acro is peeling off like if something was pecking at it but i havent found nothing pecking at the acros i dont understand and i will hopefully get a pic of the acros today and as far as mag goes im dosing ruffly about 90cc a day of mag and it doesnt go up, oh and its only some tips of certain acros not all my acros are being affected and i really appreciate the help guys and hopefully with your guys help i can figure this out thanks