I am new to the TFPM way, & oh so glad! Have the TF-100 test kit... My 16X32 IG pool has beautiful, crystal clear & sparkling water...BUT...here are the readings from last evening:
FC: 1.5
CC: 5.0 (eek!)
TC: 6.5
pH: 7.5
TA: 90
CH: 150
CYA: 70
with that CYA, I did partially drain the pool to the bottom of the skimmer, & refilled: vacuumed & backwashed the filter (DE). Looking like a SLAM is in order (right?)...w/ CYA of 70, saw that FC should be 28 w/ shock; pool calc said 855oz 8.25% bleach to up FC by 26.
Have added 8 gallons 8.25% bleach, & here are current test results:
pH: 7.2 ( but can't trust during slam, right?)
CH: 175
TA: 100
FC: 6.5
CC: 1.0
TC: 7.5
CYA: 60
Headed in right direction w/ drop in CC, but FC no where near goal of 28... Also, CYA level now 60...really am trying to get the hang of that test-- am following directions precisely; often find myself closing one eye...is that ok? Shall I recalculate my goal FC?
Would greatly appreciate guidance! Thanks!
FC: 1.5
CC: 5.0 (eek!)
TC: 6.5
pH: 7.5
TA: 90
CH: 150
CYA: 70
with that CYA, I did partially drain the pool to the bottom of the skimmer, & refilled: vacuumed & backwashed the filter (DE). Looking like a SLAM is in order (right?)...w/ CYA of 70, saw that FC should be 28 w/ shock; pool calc said 855oz 8.25% bleach to up FC by 26.
Have added 8 gallons 8.25% bleach, & here are current test results:
pH: 7.2 ( but can't trust during slam, right?)
CH: 175
TA: 100
FC: 6.5
CC: 1.0
TC: 7.5
CYA: 60
Headed in right direction w/ drop in CC, but FC no where near goal of 28... Also, CYA level now 60...really am trying to get the hang of that test-- am following directions precisely; often find myself closing one eye...is that ok? Shall I recalculate my goal FC?
Would greatly appreciate guidance! Thanks!
Typically when FC drops, we look at a couple immediate possibilities - either there is a low CYA allowing the chlorine to get burnt-off by the sun, or there is still algae in the water somewhere which is using-up the FC. By any chance, have you taken another good luck at any accessories in your pool - specifically ladder steps, rails, etc? Other pool owners have had problems with algae hiding under these sneaky areas causing the SLAM to go longer. Will rain effect your testing and levels? ... perhaps a little. Looks like you are being quite vigilant in your efforts. I don't' have a DE filter, so I'll have to let someone else speak for that one. I would continue the SLAM for now unless a TFP expert has some other advice to offer. Keep-up the great work! 
Patience and perseverance will prevail.