How about an update!
She's been completely canned food now for about 18 days. There has been only one regurgitation in the last 10 days, and that one was MY fault. I pushed her to eat more than she wanted, and she paid me back by puking it back up.
Her pH varies from 6.0 to 6.75, I'm still working on what the pattern may be, if any. The pH numbers seem highest (6.75) if she has eaten any Before Grain canned foods, which are grain free, no fruits or veggies. Lowest (6.5 or 6.25) after eating Castor&Pollux chicken and vegetable (which contains spinach, oat fiber and rice among other plant matter). Introducing the By Nature foods seems to have made her more consistent with the 6.5, but I am still gathering info.
I have to remember that her body is used to eating one food and one food only, but now that she is on canned, she is getting a variety of brands and proteins, so it will take her body some time to adjust to it.
She had a spell of diarrhea from the turkey/turkey liver By Nature, which was shocking to her and me both, as she has never in her life had diarrhea before. But with the help of ProViable DC she got back on track, and she will not have that particular By Nature again. She does well on the By Nature Beef.
Some conclusions I have made
1-I truly think my water had a lot to do with her urine becoming too alkaline, thus making a breeding ground for struvite to form.
2-I also believe that going too long without food has become a problem for her. More than 8 or 8 1/2 hours and she gets a build up of acid in her tummy, which in turn was causing her to feel sick, and bring her breakfast back up.
So before I go to bed, while they are having their last meal of the night, I prepare a dish with a small amount of food in it, to be given to her when I first get up. I sneak it to her after warming it up, just enough so she has something in her tummy, to hold her over until the real breakfast comes about 40 minutes after that. I do the same thing, preparing the dish before I leave the house in the morning, then when I get home at night, I slip her the little snack, to hold her over until the real supper starts, which is about an hour after I get home. (Little cat needs an hour of play time after I get home or she doesn't eat well)
So, while we are still experimenting with the food rotation, I am pretty happy with the way things are going.