Phosphate and calcium wouldn't effect the anemone that much.
Those parameters are more important for corals and such because they secrete calcium carbonate skeletons.
With anemones the trick about keeping them is to first get a specimen that is in good shape to begin with because they don't ship well. Anemones need tremendous lighting too, The best luck I have had is using metal halides but I have had success with VHO with some species. The next hardest part is placement, attachment issues because many anemones have very specific requirements in the substrate they live on. I hate to rant like this but I am trying to be helpful.
Could you give us more details about your system? It is really hard to tell you anything insightful without knowing anything about your tank.