There are other options for adding CYA to the pool. There is a quick-dissolving and fairly pH neutral formulation of a CYA salt called "Instant Pool Water Conditioner" made by "Natural Chemistry" and may be seen at
this link. I've never used it, but I've been in communication with the chemist who developed it so it's certainly an alternative (it's a sodium salt of CYA in a slurry). Another alternative is to use Dichlor since that is also quick-dissolving. Of course, that also increases FC, but chlorine is something you need to add every day anyway so doing a "shock" with Dichlor is one way to add a lot of CYA relatively quickly. I haven't checked comparative prices for these options.
Richard