I have a question about electricity and saline?

ok, not sure what i was thinkin, should have googled the result BEFORE i do somethin, but basically i filled a metal container with faucet water, put a little sea salt in there, then got a ac to dc transformer cable that outputs 12v dc, and i put the cable at the bottom, the water fizzled for a long time, and when i took it out, the water looks brown with green stuff in it, i used my battery tester to find out the liquid is also producing a small current, what the hell did i do?