Define "too much" - if you followed the directions on the package the flushing you've already done should be sufficient; just give them plain water for the next couple of weeks and they should recover. Likely the old growth won't return to normal but the new growth coming in should be fine. And clearly back off the amount you do use when you return to using the fert. However, if you got over-enthusiastic and added more than the directions indicate, you probably ought to flush a couple more times.
Caveat - the age of your plants makes a difference, too. Very young plants can only handle very small amounts of nutes, so would require more flushing even if you mixed according to the package directions. I am assuming that your plants are reasonably grown at this point since you are in California and not the "great white" (snowy) part of the country.