I've been reading these forums for a while now and finally got my hot tub's water all balanced. Per the instruction on this forum and using measurements from Pool Calculator I started with Dichlor until my CYA was around 50ppm and have been using bleach ever since. With the understanding that I don't want to use a chlorine based shock I bought a non-chlorine shock / oxidizer (31% potassium peryxymonosulfate).
My question is this.. should "shocking" with this oxidizer raise my FC levels back up? Does it convert used chlorine back into free or does it just "evaporate" the used chlorine? If this is the case I must continue using bleach as the FC is being used? My 300g tub will sit covered and unused at 100 degrees for a few days and FC will go from 3-5ppm to 0.. how is the FC being used up or are my expectations incorrect and I need to be out there adding bleach every day (even when not being used)?