Fill water CH is 200 (test strip)

I tested everything today as follows:
CL = 1
PH = 7.6
CYA = 50 (added stabilizer to bring up to 80)
TA = 80
CH = 1000 (test strip)
CH = 460 (pool store test).

The pool store recommended AllClear Stain and Scale for the hardness
I cleaned the salt cell yesterday and this morning it was fully clogged with scale. Flakes continue to come out of the return lines and congreagte on the step just below the return.

Is it possible that scale has built up on the walls and as it breaks up and is sucked through the filter it then clogs the salt cell?