Aww man that's no good.Hi all,
I hope you all are having a better day than I am with regards to this marine hobby. My purple tang was found dead this morning in my FOWLR, probably due to poor water quality (though ammonia and nitrites are zero but nitrates are around 160-200 ppm and brown hair algae and cyanobacteria are excessive...)
I may be wrong here, but nitrates need to be a lot higher than that to be toxic, if they even can be.
Are you oxygenating the water?