White/brown spot on monti?

[MoshJosh]

Found two weird spots on my Monty, one is about dime size, maybe a little smaller and the other is just a tiny dot. Kind of white/brown in color, Otherwise the coral looks pretty healthy to me. I get my water tested at the local store, so results are a few day old but most recently:

salinity 1.26
Ammonia 0.1 ppm (always reads this?)
Nitrite 0
Nitrate 1
pH 8.3
Alk 109
Calc 356
Mag 1435
Phos 0

 

[vetteguy53081]

Found two weird spots on my Monty, one is about dime size, maybe a little smaller and the other is just a tiny dot. Kind of white/brown in color, Otherwise the coral looks pretty healthy to me. I get my water tested at the local store, so results are a few day old but most recently:

salinity 1.26
Ammonia 0.1 ppm (always reads this?)
Nitrite 0
Nitrate 1
pH 8.3
Alk 109
Calc 356
Mag 1435
Phos 0

Tissue loss from either;
High flow
Bright white intensity
High slk
Low ca
High salinity
High phosphate
Bugs/nudibranch

things to check