I need to raise my Alkalinity.....but not my pH

[aa62579]

pH-7.8
CYA-50
TA-70
TC/FC-4ppm
I use Clorox unscented 6% bleach weekly.....only.
My fill water TA is 90, but I have had an unusual amount of rain here in Cincinnati, which I feel may be the culprit here.....

You are only adding bleach WEEKLY? Do you have a SWG? Are you using pucks? If not, have you tested your FC and CC before your next bleach addition to make sure it is still above the minimum range and <= .5 CC?