OK, so I am battling the same issue that many people have. Very low free chlorine and about 2x that in total. I have a high ammonia level and I am keeping everyone out of the pool. I am concerned that the ammonia is being caused by bacteria because the water is crystal clear and there is no algae. Richard (Chem Geek) has me on the right track and I will handle the ammonia monster on Monday.
However, I met at least two people at pool stores who have the same issues an use the pool...no problem. One guy said his pool has been like this for years! If you go to Walmart they only sell the OTO kits, (which by the way, says my pool is fine, as does Leslies) so any one that goes there for their pool supplies is only measuring total and could very well have this issue for years as well.