High reading for CC after shock treatment

[poolaris]

Still don’t understand why CC was so high. As mentioned, the spa has only been used by myself and always after a shower, also for only about 5 minutes at a time. Chlorine has always been kept at a min. of 3. Could it be that after shocking it that there was so much gunge in it that it was converted into lots of chloramines? If that was the case, how could it have got there? Strange that the water was so clear & sparkling.

[PoolDoc]

There are 3 possibilities that I can think of:

1) People goo
2) Possibly in the past, you added some sort of pool chemical that reacts badly with chlorine
3) Some sort of testing error occurred.