Authors: Godinot, C.; Chadwick, N. E.
Source: Bulletin of Marine Science, Volume 85, Number 1, July 2009, pp. 1-9(9)
Publisher: University of Miami – Rosenstiel School of Marine and Atmospheric Science
(Also on ResearchGate: Phosphate excretion by anemonefish and uptake by giant sea anemones: Demand outstrips supply)
Full article avalable.
We conclude that under laboratory conditions, anemones absorb phosphate up to 6.6× faster than the rate at which it is excreted by their anemonefish, and thus fish do not appear to provide sufficient phosphate to their hosts through this pathway. Anemones may get most of their phosphorus via ingestion of fish feces and/or mucus, or via the ingestion of prey.
Folks should consider growing anemones if they have phosphate issues!
This is also consistent with info here: