The acute aquatic toxicities (narcoses) for a range of organism types may be estimated with LSER for a large number of inorganic and organometal species, many with an accuracy at or within an order of magnitude. Optimum estimations make use of a bioavailable metal fraction and a more accurate structure(s) for the toxic solution species. The estimated toxicities for a number of salts were quite different from the observed values, likely due to a dominant specific toxicity mechanism other than baseline narcosis. The tool still requires fine-tuning.