RE: Not Entirely New BUT?????
Welcom to MAAST!
We've had the discussion about water and everything else from the coast several times. I think the main argument against it is that you are in a major urban and industrial area and the water there is not exactly of the same quality you would find on a reef in the South Pacific. Running sea water through activated carbon should remove the organics but there is still an issue with heavy metals. Personally I wouldn't thin metals would be as much of an issue as organics.
Gary
125 SPS, 75 gal. LPS/softie reef, 9 gal. Nano