New vet sounds awesome!
I called around all the companies I liked and found that several had the target urine pH that the science diet c/d has (6.2-6.4) or were very near.
Also increased water input by making "soup" out of canned... 1 teaspoon canned and 1/4 cup water at lunch time just to get more water in to flush their bladders.
IIRC, the foods that had the ok pH were PetGuard (dry/canned), Bil-Jac select. All the others I called on were 6.6-7.4 depending on brand.
Definitely would try a canned food for a while.
Oh, I see that is wasn't crystals after all. Well great news :)