Expert HELP needed! Mystery problem - Corals dying.... Out of ideas?!

[Timfish]

Thanks as in its to low or to high? Test is usually around 0.01 - that’s what the triton test came back with to. I thought a small amount like Th at was ideal?

Research done at SOuthampton University in England found .03 mg/l to be a threshold level with their experiments.

The link for I posted above for one of their papers has been removed so here's an updated link for thier first paper published on the long term experiments they did (are doing).

Phosphate Deficiency:
Nutrient enrichment can increase the susceptibility of reef corals to bleaching:

Nutrient enrichment can increase the susceptibility of reef corals to bleaching - Nature Climate Change

Increased dissolved inorganic nitrogen (DIN) concentrations in sea water have been linked to a reduction of the temperature threshold at which corals bleach, however, the mechanism underlying this change is not known. This phenomenon is now explained in terms of increased phosphatase activities...

www.nature.com