Torches Bleaching

[Lil Puff]

Hi guys, what causes torches to bleach randomly then just disintegrate? It affects one head then the next head starts to bleach as the first one dissolves. Some sps aren’t looking to crash happy either. Any help appreciated. I have attached images but are a bit cloudy as I just cleaned glass. Thanks!

Alk - 7.85
Nitrate - 10.3
Phosphate - 0.09
Calcium - 440
Magnesium- 1305

see dead torch head and freshly disintegrated head next to it below. Above is a healthy torch. To the left of the dead torch is another torch that one head is bleached on.

Partly bleached torch

unhappy sps

front tank shot

 

[nautical_nathaniel]

Alk is pretty low, especially for SPS.

Any big changes to the tank recently? Are you using RODI water when doing water changes? How often and how big are your water changes? Running carbon or any other chemical media? Have you checked your magnets or any other metallic parts inside the tank for signs of corrosion? (I had a magnet dissentigrating in my tank one time that caused similar issues)