Send a sample of NSW to ATI or Triton.
I use NSW from the North Sea, Netherlands pumped at high tide on 6 meters depth.
My test results of ATI of NSW North Sea Water.
//lab.atiaquaristik.com/share/44e2c698916cfa816db0
I think not bad!
I stock the 30 litres Jerry cans in my garage with the cap on it.
For use I filter by filter wool, for any floating particles, algae or something.
Normally I use all stock within 2 months, this smells than fresh to the sea.
A 15% WC every week, the corals grow very fast.
I use a seawater-resistant 120 volt bilge pump of only €59
250 litres pumped in 10 minutes.