I am so sorry your losing your fish. I would also second the idea of some daily large water changes. I hope this works for you and you do not lose anymore.
Sorry to hear bro. Since your in cali, I wood call the county or city about the water supply. I know umbeeking and Ruck Fules had a similar situation last year around this time. Supposedly the city added extra chemicals to the water. When those guys noticed issues with their tank they tested water and nothing so they did water changes like anyone else would. But that in fact made matters worse!!! So be careful bro and good luck. Maybe gani or Chris could shed some more light on this since they were the ones who experienced this...