Checked FC yesterday afternoon. The reading was down to 7, so I added 32 oz of cal-hypo. I checked FC in the evening and it was still up at 13. I vacuumed out the pool last night. This morning I checked the FC at it was still at 13, so hopefully I've got everything cleared out.
As a side question, I've got another basic test kit that using a chlorine neutralizer before testing for PH. Is it possible to get an accurate reading for PH using that style of test during a SLAM? I'm not sure of the chemistry involved with the PH reagents.