Many people in the San Diego area use water from Birch Aquarum at Scripps. They pull it from the end of the Scripps Pier (college) and filter it for their aquarium. They offer it to hobbyists free of charge. I haven't got any lately because of the rain causing poor water quality. We just store it in the dark for a few weeks before use. I have about 10 containers that I cycle. I've had excellent luck with it. If you keep corals, test it to see if you need to add magnesium or calcium. (you should be testing all params anyway since it's coming straight off the ocean)
"How can I get seawater for my aquarium/business?
The seawater tap at the base of the Scripps Pier is open to the public 24 hours a day. The water is sent through sand filters to remove the larger particles. This is the same seawater used by aquarists at the Birch Aquarium at Scripps. The Scripps Pier is located at the end of Discovery Way. Take La Jolla Shores Drive to the Naga Way entrance; turn west onto Naga Way; at the split, turn left to continue on Naga Way; at the stop sign, turn right onto Discovery Way; the pier will be directly in front of you and the tap is to the left of the pier entrance. If you have further questions about the seawater tap, please e-mail the aquarists at Birch Aquarium at Scripps:
aquariuminfo@ucsd.edu."
http://sio.ucsd.edu/About/Scripps_Ov...Qs/#question16